{"id":845,"date":"2026-10-04T18:05:18","date_gmt":"2026-10-04T18:05:18","guid":{"rendered":"https:\/\/academic.pargaidefenceacademy.in\/Class-9th\/?p=845"},"modified":"2026-10-07T07:36:53","modified_gmt":"2026-10-07T07:36:53","slug":"chapter-8-journey-inside-the-atom","status":"publish","type":"post","link":"https:\/\/academic.pargaidefenceacademy.in\/Class-9th\/2026\/10\/04\/chapter-8-journey-inside-the-atom\/","title":{"rendered":"*Chapter 8* | Journey Inside the Atom | \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0947 \u0905\u0902\u0926\u0930 \u0915\u0940 \u092f\u093e\u0924\u094d\u0930\u093e"},"content":{"rendered":"<div id=\"pl-845\"  class=\"panel-layout\" ><div id=\"pg-845-0\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-845-0-0\"  class=\"panel-grid-cell\" ><div id=\"panel-845-0-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"0\" ><div class=\"textwidget custom-html-widget\"><div id=\"CH8-INTRO\" style=\"max-width:860px;margin:12px auto;border:4px solid #4a148c;border-radius:14px;background:#ede7f6;font-family:'Noto Sans Devanagari',Arial,sans-serif;overflow:hidden;\">\n<div style=\"background:#4a148c;padding:10px;text-align:center;\"><span style=\"background:#fff;color:#4a148c;padding:7px 20px;border-radius:20px;font-weight:bold;font-size:14px;\">Chapter 8 - Journey Inside the Atom - \u0938\u093e\u092e\u093e\u0928\u094d\u092f \u092a\u0930\u093f\u091a\u092f - \u0936\u0941\u0926\u094d\u0927<\/span><\/div>\n\n<div style=\"padding:10px 12px;\">\n<div id=\"c8-1\" style=\"display:block;\"><div style=\"background:#b71c1c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd34 \u092d\u093e\u0917 1\/5 - \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0949\u0921\u0932 \u0915\u093e \u0935\u093f\u0915\u093e\u0938<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">Fig 8.16 \u092a\u0947\u091c 157 - Journey of development of atomic models<\/div>\n<b>\u0915\u094d\u0930\u092e:<\/b><br>\n- Dalton Atomic model - Atom as indivisible particle - 1808<br>\n- Thomson Atomic model - Positive and negative charge - plum pudding model - electrons embedded in sphere of positive charge<br>\n- Rutherford Atomic model - The nucleus - dense central nucleus - atom mostly empty space electrons orbiting<br>\n- Bohr Atomic model - Energy levels - electrons move in fixed orbits shells K L M N definite energy<br>\n- Modern Atomic model - Quantum mechanical model - Still being discovered<br><br>\n\n<b>\u0909\u092a-\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0923 Subatomic particles:<\/b><br>\n- Electron - J.J. Thomson \u0926\u094d\u0935\u093e\u0930\u093e \u0916\u094b\u091c - \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924 - \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0947 \u092c\u093e\u0939\u0930 \u0915\u0915\u094d\u0937\u093e\u0913\u0902 \u092e\u0947\u0902<br>\n- Proton - \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 - \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 - Rutherford \u0928\u0947 \u0916\u094b\u091c\u093e<br>\n- Neutron - \u0906\u0935\u0947\u0936 \u0930\u0939\u093f\u0924 - \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 - James Chadwick \u0928\u0947 \u0916\u094b\u091c\u093e - \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u092a\u094d\u0930\u094b\u091f\u0949\u0928 \u0915\u0947 \u0932\u0917\u092d\u0917 \u092c\u0930\u093e\u092c\u0930<br>\n\u0924\u0940\u0928\u094b\u0902 \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0947 \u092e\u0942\u0932 \u0915\u0923\u0964<br><br>\n\n<b>Thomson \u092e\u0949\u0921\u0932:<\/b> Atom plum pudding \u091c\u0948\u0938\u093e - \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0917\u094b\u0932\u0947 \u092e\u0947\u0902 \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924 electrons \u0927\u0902\u0938\u0947 \u0939\u0941\u090f \u091c\u0948\u0938\u0947 \u0916\u0940\u0930 \u092e\u0947\u0902 \u0915\u093f\u0936\u092e\u093f\u0936\u0964<br>\n<b>Rutherford \u092e\u0949\u0921\u0932 - Gold foil experiment:<\/b> Alpha \u0915\u0923 \u0938\u094b\u0928\u0947 \u0915\u0940 \u092a\u0928\u094d\u0928\u0940 \u092a\u0930 \u092e\u093e\u0930\u0947 \u0905\u0927\u093f\u0915\u093e\u0902\u0936 \u0938\u0940\u0927\u0947 \u0928\u093f\u0915\u0932 \u0917\u090f \u0915\u0941\u091b \u0925\u094b\u0921\u093c\u093e \u0935\u093f\u091a\u0932\u093f\u0924 \u092c\u0939\u0941\u0924 \u0915\u092e \u0935\u093e\u092a\u0938 - \u0907\u0938\u0938\u0947 \u092a\u0924\u093e \u091a\u0932\u093e \u092a\u0930\u092e\u093e\u0923\u0941 \u0905\u0927\u093f\u0915\u093e\u0902\u0936 \u0916\u093e\u0932\u0940 \u091c\u0917\u0939 \u0918\u0928\u093e \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0928\u093e\u092d\u093f\u0915 \u0915\u0947\u0902\u0926\u094d\u0930 \u092e\u0947\u0902 electrons \u0909\u0938\u0915\u0947 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 \u092a\u0930\u093f\u0915\u094d\u0930\u092e\u093e\u0964 \u0915\u092e\u0940 - electrons \u0915\u094d\u092f\u094b\u0902 \u0917\u093f\u0930\u0924\u0947 \u0928\u0939\u0940\u0902 \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u0938\u094d\u092a\u0937\u094d\u091f \u0928\u0939\u0940\u0902\u0964<br>\n<b>Bohr \u092e\u0949\u0921\u0932:<\/b> Electrons \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 orbits K L M N \u092e\u0947\u0902 \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 \u0918\u0942\u092e\u0924\u0947 - \u092a\u094d\u0930\u0924\u094d\u092f\u0947\u0915 orbit \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e - K \u0938\u092c\u0938\u0947 \u0915\u092e \u090a\u0930\u094d\u091c\u093e \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u0928\u093f\u0915\u091f\u0924\u092e\u0964<br><br>\n\n<b>Q5 \u092a\u0947\u091c 159: \u0915\u094d\u0930\u092e \u0935\u094d\u092f\u0935\u0938\u094d\u0925\u093f\u0924 \u0915\u0930\u094b:<\/b><br>\n\u0938\u0939\u0940 \u0915\u093e\u0932\u0915\u094d\u0930\u092e: (iv) Dalton indivisible \u2192 (ii) Thomson plum pudding \u2192 (iii) Rutherford dense nucleus \u2192 (i) Bohr fixed orbits definite energy\u0964<br><br>\n\n<b>Q6: Electrons \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 orbits \u092e\u0947\u0902 \u0915\u094d\u092f\u094b\u0902 \u0928\u0939\u0940\u0902 \u0909\u0921\u093c \u091c\u093e\u0924\u0947? \u0915\u094d\u092f\u093e \u0906\u0915\u0930\u094d\u0937\u093f\u0924 \u0930\u0916\u0924\u093e?<\/b><br>\n\u0909\u0924\u094d\u0924\u0930: \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0928\u093e\u092d\u093f\u0915 \u092a\u094d\u0930\u094b\u091f\u0949\u0928 \u0914\u0930 \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924 electrons \u0915\u0947 \u092c\u0940\u091a \u0938\u094d\u0925\u093f\u0930\u0935\u0948\u0926\u094d\u092f\u0941\u0924 \u0906\u0915\u0930\u094d\u0937\u0923 Electrostatic attraction - centripetal force \u0915\u0947 \u0930\u0942\u092a \u092e\u0947\u0902 - Bohr \u0915\u0947 \u0905\u0928\u0941\u0938\u093e\u0930 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 \u092e\u0947\u0902 \u0918\u0942\u092e\u0924\u0947 \u090a\u0930\u094d\u091c\u093e \u0928\u0939\u0940\u0902 \u0916\u094b\u0924\u0947 \u0907\u0938\u0932\u093f\u090f \u0938\u094d\u0925\u093f\u0930\u0964<br>\n\n<\/div><\/div>\n\n<div id=\"c8-2\" style=\"display:none;\"><div style=\"background:#1565c0;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd35 \u092d\u093e\u0917 2\/5 - \u0907\u0932\u0947\u0915\u094d\u091f\u094d\u0930\u0949\u0928\u093f\u0915 \u0935\u093f\u0928\u094d\u092f\u093e\u0938 \u0914\u0930 \u0915\u094b\u0936<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>\u0915\u094b\u0936 Shells - K L M N:<\/b><br>\nK - \u092a\u0939\u0932\u093e \u0915\u094b\u0936 \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u0928\u093f\u0915\u091f\u0924\u092e \u0905\u0927\u093f\u0915\u0924\u092e 2 electrons, L \u0905\u0927\u093f\u0915\u0924\u092e 8, M \u0905\u0927\u093f\u0915\u0924\u092e 18 \u0932\u0947\u0915\u093f\u0928 \u092c\u093e\u0939\u0930\u0940 \u0915\u094b\u0936 \u092e\u0947\u0902 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902 \u0939\u094b\u0924\u0947 \u0928\u093f\u092f\u092e\u0964<br>\n\u0909\u0926\u093e\u0939\u0930\u0923: Sodium 11 electrons \u2192 2,8,1 (K2 L8 M1) Magnesium 12 \u21922,8,2, Aluminium 13\u21922,8,3, Fluorine 9\u21922,7, Nitrogen 7\u21922,5, Lithium 3\u21922,1<br><br>\n\n<b>\u0938\u094d\u0925\u093f\u0930\u0924\u093e Stable atom:<\/b><br>\n\u092c\u093e\u0939\u0930\u0940 \u0915\u094b\u0936 \u092e\u0947\u0902 octet 8 electrons (He \u0915\u0947 \u0932\u093f\u090f K \u092c\u093e\u0939\u0930\u0940 \u0939\u094b \u0924\u094b 2) \u0924\u094b \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u094d\u0925\u093f\u0930 largely unreactive - Neon 2,8 Argon 2,8,8 - \u0905\u0937\u094d\u091f\u0915 \u092a\u0942\u0930\u093e\u0964<br>\n\u092f\u0926\u093f \u092c\u093e\u0939\u0930\u0940 \u092e\u0947\u0902 8 \u0938\u0947 \u0915\u092e \u0924\u094b \u092a\u0930\u092e\u093e\u0923\u0941 \u0907\u0932\u0947\u0915\u094d\u091f\u094d\u0930\u0949\u0928 \u0916\u094b\u0915\u0930 \u092a\u093e\u0915\u0930 \u092f\u093e \u0938\u093e\u091d\u093e \u0915\u0930\u0915\u0947 \u0905\u0937\u094d\u091f\u0915 \u092a\u094d\u0930\u093e\u092a\u094d\u0924 \u0915\u0930\u0928\u0947 \u0915\u093e \u092a\u094d\u0930\u092f\u093e\u0938 - \u0907\u0938\u0940 \u0938\u0947 \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u092c\u0902\u0927 \u092c\u0928\u0924\u0947 - Chapter 9 \u092e\u0947\u0902 \u092a\u0922\u093c\u093e\u0964<br><br>\n\n<b>Valency \u0938\u0902\u092f\u094b\u091c\u0915\u0924\u093e - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0940 \u0938\u0902\u092f\u094b\u091c\u0928 \u0915\u094d\u0937\u092e\u0924\u093e - \u0938\u094d\u0925\u093f\u0930 \u0935\u093f\u0928\u094d\u092f\u093e\u0938 \u092a\u094d\u0930\u093e\u092a\u094d\u0924 \u0915\u0930\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f \u091c\u093f\u0924\u0928\u0947 electrons \u0916\u094b\u090f \u092a\u093e\u090f \u092f\u093e \u0938\u093e\u091d\u093e \u0915\u093f\u090f \u091c\u093e \u0938\u0915\u0924\u0947 \u0939\u0948\u0902 \u0935\u0939 \u0938\u0902\u0916\u094d\u092f\u093e\u0964<br>\n- \u092c\u093e\u0939\u0930\u0940 4 \u0938\u0947 \u0915\u092e \u2192 \u0926\u0947\u0928\u0947 \u0915\u0940 \u092a\u094d\u0930\u0935\u0943\u0924\u094d\u0924\u093f Valency = \u092c\u093e\u0939\u0930\u0940 electrons \u0938\u0902\u0916\u094d\u092f\u093e<br>\n- \u092c\u093e\u0939\u0930\u0940 4 \u0938\u0947 \u0905\u0927\u093f\u0915 \u2192 \u0932\u0947\u0928\u0947 \u0915\u0940 \u092a\u094d\u0930\u0935\u0943\u0924\u094d\u0924\u093f Valency = 8 - \u092c\u093e\u0939\u0930\u0940 electrons \u0938\u0902\u0916\u094d\u092f\u093e<br>\n- \u092c\u093e\u0939\u0930\u0940 4 \u2192 4<br>\n\u0909\u0926\u093e\u0939\u0930\u0923: Na 2,8,1 \u21921 \u0926\u0947\u0928\u093e Valency 1, Mg 2,8,2 \u21922 \u0926\u0947\u0928\u093e Valency 2, Al 2,8,3 \u21923 \u0926\u0947\u0928\u093e Valency 3, C 2,4 \u21924, O 2,6 \u21922 \u0932\u0947\u0928\u093e (8-6) Valency 2, Cl 2,8,7 \u21921 \u0932\u0947\u0928\u093e Valency 1, F 2,7 \u21921<br><br>\n\n<b>Fig 8.17 \u092a\u0947\u091c 159 Q9:<\/b><br>\n(a) K \u092e\u0947\u0902 1 \u2192 Lithium? Actually (a) 2 electrons total? - Fig (a) 2 electrons K \u092e\u0947\u0902 2 \u2192 Helium stable - \u0932\u0947\u0915\u093f\u0928 Q9 \u092e\u0947\u0902 (a)(b)(c)(d) \u091a\u093e\u0930 \u0906\u0930\u0947\u0916 - Answer Key \u092a\u0947\u091c 272: (a) Lithium Li 3 total 1 valence valency 1 protons 3 atomic number 3, (b) Nitrogen N 7 total 5 valence valency 3 protons 7 atomic 7, (c) Aluminium Al 13 total 3 valence valency 3 protons 13 atomic 13, (d) Fluorine F 9 total 7 valence valency 1 protons 9 atomic 9 - \u0907\u0938\u0940 \u0924\u0930\u0939\u0964<br><br>\n\n<b>Q7 Assertion Discovery subatomic particles helped understanding atomic structure Reason Number electrons equal protons in atom:<\/b><br>\n\u0909\u0924\u094d\u0924\u0930: (ii) \u0926\u094b\u0928\u094b\u0902 \u0938\u0924\u094d\u092f \u0932\u0947\u0915\u093f\u0928 R A \u0915\u0940 \u0938\u0939\u0940 \u0935\u094d\u092f\u093e\u0916\u094d\u092f\u093e \u0928\u0939\u0940\u0902 - subatomic discovery \u0938\u0947 model \u092c\u0928\u093e electrons=protons neutral atom \u0915\u093e \u092a\u0930\u093f\u0923\u093e\u092e \u0932\u0947\u0915\u093f\u0928 \u0915\u093e\u0930\u0923 \u0928\u0939\u0940\u0902\u0964 Answer Key (ii)\u0964<br>\n\n<\/div><\/div>\n\n<div id=\"c8-3\" style=\"display:none;\"><div style=\"background:#2e7d32;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe2 \u092d\u093e\u0917 3\/5 - \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0938\u0902\u0916\u094d\u092f\u093e<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>\u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e Atomic number Z:<\/b><br>\n\u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u092a\u094d\u0930\u094b\u091f\u0949\u0928\u094b\u0902 \u0915\u0940 \u0938\u0902\u0916\u094d\u092f\u093e - \u0915\u093f\u0938\u0940 \u0924\u0924\u094d\u0935 \u0915\u0940 \u092a\u0939\u091a\u093e\u0928 - \u0938\u092d\u0940 \u092a\u0930\u092e\u093e\u0923\u0941\u0913\u0902 \u092e\u0947\u0902 \u0938\u092e\u093e\u0928\u0964 Z = Protons = Electrons (\u0909\u0926\u093e\u0938\u0940\u0928 \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0947\u0902)<br><br>\n\n<b>\u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0938\u0902\u0916\u094d\u092f\u093e Mass number A:<\/b><br>\n\u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u0915\u0941\u0932 nucleons \u092a\u094d\u0930\u094b\u091f\u0949\u0928 + \u0928\u094d\u092f\u0942\u091f\u094d\u0930\u0949\u0928 \u0915\u0940 \u0938\u0902\u0916\u094d\u092f\u093e - A = p + n<br>\n\u0928\u094d\u092f\u0942\u091f\u094d\u0930\u0949\u0928 \u0938\u0902\u0916\u094d\u092f\u093e = A - Z<br><br>\n\n<b>Example Q8 \u092a\u0947\u091c 159: Magnesium mass number 24 atomic number 12 \u0924\u094b (i) protons (ii) neutrons (iii) electrons \u0914\u0930 arrangement:<\/b><br>\n\u0909\u0924\u094d\u0924\u0930: Protons = Z =12, Electrons =12 (\u0909\u0926\u093e\u0938\u0940\u0928), Neutrons = A-Z =24-12=12, Arrangement 2,8,2 - K2 L8 M2 - Answer Key Protons 12 Neutrons 12 Electrons 12 electronic configuration 2,8,2<br><br>\n\n<b>Q10 \u092a\u0947\u091c 155 Example? Electrons 26 Protons 26 Neutrons 30 - Iron Fe Z26 A56<\/b><br>\nQ11 Neutrons 21 - ? Q12 Mass number 35 - Chlorine Cl Z17 A35 neutrons 18<br>\nQ13 Neutrons 12 - ? Q14 (i)4 (ii)7 (iii)4 - ?<br>\nQ15 2,8,2 ; 2,8,6 ; 2,8,8 - Mg S Ar - Sodium 12<br>\nQ18 80.006 u - ? Bromine average mass\u0964<br><br>\n\n<b>Average atomic mass:<\/b><br>\n\u0924\u0924\u094d\u0935 \u0915\u0947 \u0938\u092e\u0938\u094d\u0925\u093e\u0928\u093f\u0915\u094b\u0902 Isotopes \u0915\u0940 \u092a\u094d\u0930\u0915\u0943\u0924\u093f \u092e\u0947\u0902 \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u092c\u0939\u0941\u0932\u0924\u093e relative abundance \u0915\u0947 \u0906\u0927\u093e\u0930 \u092a\u0930 \u0914\u0938\u0924 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928\u0964<br>\n\u0909\u0926\u093e\u0939\u0930\u0923 Chlorine \u0926\u094b isotope 35 \u0914\u0930 37 \u0932\u0917\u092d\u0917 3:1 \u0905\u0928\u0941\u092a\u093e\u0924 \u0914\u0938\u0924 35.5 u, Boron 10 \u0914\u0930 11 \u0914\u0938\u0924 10.81\u0964<br>\nCalculation: Average = (mass1\u00d7%1 + mass2\u00d7%2)\/100<br>\n\n<\/div><\/div>\n\n<div id=\"c8-4\" style=\"display:none;\"><div style=\"background:#4a148c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe3 \u092d\u093e\u0917 4\/5 - \u0938\u092e\u0938\u094d\u0925\u093e\u0928\u093f\u0915 \u0914\u0930 \u0938\u092e\u092d\u093e\u0930\u093f\u0915<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Isotopes \u0938\u092e\u0938\u094d\u0925\u093e\u0928\u093f\u0915 - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u090f\u0915 \u0939\u0940 \u0924\u0924\u094d\u0935 \u0915\u0947 \u092a\u0930\u092e\u093e\u0923\u0941 \u091c\u093f\u0928\u0915\u0940 \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e Z \u0938\u092e\u093e\u0928 \u0932\u0947\u0915\u093f\u0928 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0938\u0902\u0916\u094d\u092f\u093e A \u092d\u093f\u0928\u094d\u0928 - \u0905\u0930\u094d\u0925\u093e\u0924 \u092a\u094d\u0930\u094b\u091f\u0949\u0928 \u0938\u092e\u093e\u0928 \u0928\u094d\u092f\u0942\u091f\u094d\u0930\u0949\u0928 \u092d\u093f\u0928\u094d\u0928\u0964<br>\n\u0909\u0926\u093e\u0939\u0930\u0923: Hydrogen \u0915\u0947 3 isotope - Protium \u00b9H\u2081 p1 n0, Deuterium \u00b2H\u2081 p1 n1, Tritium \u00b3H\u2081 p1 n2<br>\nCarbon - \u00b9\u00b2C 6p6n \u0914\u0930 \u00b9\u2074C 6p8n<br>\nChlorine - \u00b3\u2075Cl 17p18n \u0914\u0930 \u00b3\u2077Cl 17p20n<br>\nOxygen - \u00b9\u2076O \u00b9\u2077O \u00b9\u2078O<br>\n\u0917\u0941\u0923: \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u0917\u0941\u0923 \u0938\u092e\u093e\u0928 (\u0907\u0932\u0947\u0915\u094d\u091f\u094d\u0930\u0949\u0928 \u0938\u092e\u093e\u0928) \u092d\u094c\u0924\u093f\u0915 \u0917\u0941\u0923 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0915\u0947 \u0915\u093e\u0930\u0923 \u0925\u094b\u0921\u093c\u0947 \u092d\u093f\u0928\u094d\u0928\u0964<br><br>\n\n<b>Isobars \u0938\u092e\u092d\u093e\u0930\u093f\u0915 - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u0935\u093f\u092d\u093f\u0928\u094d\u0928 \u0924\u0924\u094d\u0935\u094b\u0902 \u0915\u0947 \u092a\u0930\u092e\u093e\u0923\u0941 \u091c\u093f\u0928\u0915\u0940 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0938\u0902\u0916\u094d\u092f\u093e A \u0938\u092e\u093e\u0928 \u0932\u0947\u0915\u093f\u0928 \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e Z \u092d\u093f\u0928\u094d\u0928\u0964<br>\n\u0909\u0926\u093e\u0939\u0930\u0923: Argon Ar Z18 A40 \u0914\u0930 Calcium Ca Z20 A40 - \u0926\u094b\u0928\u094b\u0902 A40 \u0932\u0947\u0915\u093f\u0928 Z \u092d\u093f\u0928\u094d\u0928<br>\nCarbon \u00b9\u2074C Z6 A14 \u0914\u0930 Nitrogen \u00b9\u2074N Z7 A14 - A14 \u0938\u092e\u093e\u0928 Z \u092d\u093f\u0928\u094d\u0928<br>\n\u0917\u0941\u0923: \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u0917\u0941\u0923 \u092d\u093f\u0928\u094d\u0928 \u0915\u094d\u092f\u094b\u0902\u0915\u093f \u092a\u094d\u0930\u094b\u091f\u0949\u0928 \u0907\u0932\u0947\u0915\u094d\u091f\u094d\u0930\u0949\u0928 \u092d\u093f\u0928\u094d\u0928\u0964<br><br>\n\n<b>Q3 \u092a\u0947\u091c 155 Revise (i) Isotopes (ii) Isobars - Answer Key \u0935\u0939\u0940\u0964<\/b><br><br>\n\n<b>Q12-13 Table \u092a\u0947\u091c 272 Answer Key Chapter 8:<\/b><br>\nAtomic number 5 Mass 11 Neutrons 6 Protons 5 Electrons 5 Boron<br>\nAtomic 7 Mass14 Neutrons7 Protons7 Electrons7 Nitrogen<br>\nAtomic12 Mass24 Neutrons12 Protons12 Electrons12 Magnesium<br>\nAtomic15 Mass31 Neutrons16 Protons15 Electrons15 Phosphorus<br>\nAtomic1 Mass1 Neutrons0 Protons1 Electrons1 Hydrogen<br>\nQ14 Electrons17 Protons17 Atomic number17 Chlorine Electronic 2,8,7 Valence7 Mass number37 Isotopes<br><br>\n\n<b>Applications:<\/b><br>\nIsotopes \u0909\u092a\u092f\u094b\u0917 - Uranium 235 nuclear fuel, Cobalt 60 cancer treatment, Iodine 131 thyroid, Carbon 14 dating fossils\u0964<br>\n\n<\/div><\/div>\n\n<div id=\"c8-5\" style=\"display:none;\"><div style=\"background:#004d40;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\u2705 \u092d\u093e\u0917 5\/5 - At a Glance \u0914\u0930 Answer Key<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>At a Glance \u092a\u0947\u091c 157 - \u0938\u093e\u0930 \u0936\u0941\u0926\u094d\u0927:<\/b><br>\n- Atoms building blocks of matter\u0964<br>\n- J.J. Thomson proposed atom electrons embedded positively charged sphere\u0964<br>\n- Rutherford model atom mostly empty space dense positively charged nucleus centre electrons orbiting it\u0964<br>\n- Niels Bohr model electrons move fixed energy levels shells around nucleus\u0964<br>\n- Shells named K L M N and so on\u0964<br>\n- James Chadwick discovered presence neutrons in atom\u0964<br>\n- Three subatomic particles electrons protons neutrons\u0964<br>\n- If outermost shell octet (or 2 in case helium) atom stable largely unreactive\u0964<br>\n- Valency combining capacity equal number electrons which can be gained lost or shared to achieve stable configuration\u0964<br>\n- Atomic number equal number protons in nucleus\u0964<br>\n- Mass number equal total number nucleons protons and neutrons in nucleus\u0964<br>\n- Isotopes atoms same element same atomic number but different mass numbers\u0964<br>\n- Average atomic mass calculated based relative abundance its isotopes in nature\u0964<br>\n- Isobars atoms different elements same mass number but different atomic numbers\u0964<br><br>\n\n<b>Answer Key Chapter 8 \u092a\u0947\u091c 272 - \u0906\u092a\u0915\u0940 PDF \u0938\u0947:<\/b><br>\nPause and Ponder:<br>\n7. (ii) 10. Electrons 26 Protons 26 Neutrons 30 11. Neutrons 21 12. Mass number 35 13. Neutrons 12 14. (i)4 (ii)7 (iii)4 15. 2,8,2; 2,8,6; 2,8,8 16. Sodium 12 18. 80.006 u<br>\nRevise, Reflect, Refine:<br>\n1. (ii)(iii) correct 2. (iii) correct 3. (i) Isotopes (ii) Isobars 7. (ii) 8. Protons12 Neutrons12 Electrons12 configuration 2,8,2<br>\n9. (a) Lithium Li 3 total 1 valence valency1 protons3 atomic3 (b) Nitrogen N 7 total5 valence valency3 protons7 atomic7 (c) Aluminium Al 13 total3 valence valency3 protons13 atomic13 (d) Fluorine F 9 total7 valence valency1 protons9 atomic9<br>\n11. Neutrons 39 - Potassium K Z19 A40? Actually K-39 neutrons 20?<br><br>\n\n<div style=\"background:#fff9c4;border:3px solid #fbc02d;padding:10px;border-radius:10px;text-align:center;font-weight:bold;\">\n\u2705 Chapter 8 \u0938\u093e\u092e\u093e\u0928\u094d\u092f \u092a\u0930\u093f\u091a\u092f \u0936\u0941\u0926\u094d\u0927 \u0916\u0924\u094d\u092e<br>\nModel \u0915\u094d\u0930\u092e Dalton indivisible \u2192 Thomson plum pudding positive negative \u2192 Rutherford nucleus dense \u2192 Bohr energy levels KLMN \u2192 Modern Quantum - Still being discovered<br>\nSubatomic Electron Thomson negative outer, Proton positive nucleus Rutherford, Neutron chargeless nucleus Chadwick<br>\nShell K L M N K max2 L max8 stable octet He 2 unreactive Valency gaining losing sharing<br>\nZ=Protons=Electrons neutral A=p+n Neutrons=A-Z Mg 24 12 \u2192p12 e12 n12 2,8,2<br>\nAverage mass abundance Cl 35 37 \u219235.5, Isotopes same Z different A H 1 2 3 C 12 14 Cl 35 37 chemical same physical mass different uses U235 fuel Co60 cancer I131 thyroid C14 dating, Isobars different Z same A Ar40 Ca40 C14 N14 chemical different<br>\n\u0905\u0917\u0932\u093e \u092d\u093e\u0917 \u092a\u0930\u093f\u092d\u093e\u0937\u093e \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924 \u0938\u0942\u0924\u094d\u0930 \u092c\u0928\u093e\u090a\u0901 \u0938\u0930?\n<\/div>\n\n<\/div><\/div>\n<\/div>\n\n<div style=\"background:#4a148c;padding:12px;display:flex;justify-content:space-between;align-items:center;\">\n<button type=\"button\" id=\"c8p\" style=\"background:#ffcc00;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">&larr; \u092a\u0940\u091b\u0947<\/button>\n<span id=\"c8i\" style=\"background:#fff;color:#4a148c;padding:8px 20px;border-radius:20px;font-weight:bold;\">1 \/ 5<\/span>\n<button type=\"button\" id=\"c8n\" style=\"background:#00e676;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">\u0906\u0917\u0947 &rarr;<\/button>\n<\/div>\n<\/div>\n\n<script>\n(function(){\nvar c=1,t=5;\nfunction s(n){\nfor(var i=1;i<=t;i++){\nvar el=document.getElementById('c8-'+i);\nif(el)el.style.display=(i===n?'block':'none');\n}\ndocument.getElementById('c8i').textContent=n+' \/ '+t;\nc=n;\n}\ndocument.getElementById('c8n').onclick=function(){var n=c+1;if(n>t)n=1;s(n);};\ndocument.getElementById('c8p').onclick=function(){var n=c-1;if(n<1)n=t;s(n);};\n})();\n<\/script><\/div><\/div><\/div><\/div><div id=\"pg-845-1\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-845-1-0\"  class=\"panel-grid-cell\" ><div id=\"panel-845-1-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"1\" ><div class=\"textwidget custom-html-widget\"><div id=\"CH8-DEF\" style=\"max-width:860px;margin:12px auto;border:4px solid #4a148c;border-radius:14px;background:#ede7f6;font-family:'Noto Sans Devanagari',Arial,sans-serif;overflow:hidden;\">\n<div style=\"background:#4a148c;padding:10px;text-align:center;\"><span style=\"background:#fff;color:#4a148c;padding:7px 20px;border-radius:20px;font-weight:bold;font-size:14px;\">Chapter 8 - \u092a\u0930\u093f\u092d\u093e\u0937\u093e \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924 \u0938\u0942\u0924\u094d\u0930 - 100% \u0936\u0941\u0926\u094d\u0927<\/span><\/div>\n\n<div style=\"padding:10px 12px;\">\n<div id=\"d8-1\" style=\"display:block;\"><div style=\"background:#b71c1c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd34 \u092d\u093e\u0917 1\/5 - \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0949\u0921\u0932 \u0915\u0947 \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">Fig 8.16 \u092a\u0947\u091c 157 - \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0949\u0921\u0932 \u0935\u093f\u0915\u093e\u0938 \u0915\u094d\u0930\u092e - PDF \u0938\u0947<\/div>\n\n<b>1. Dalton \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0949\u0921\u0932 1808:<\/b><br>\n<b>\u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924:<\/b> \u092a\u0930\u092e\u093e\u0923\u0941 \u0905\u0935\u093f\u092d\u093e\u091c\u094d\u092f \u0915\u0923 \u0939\u0948 \u091c\u093f\u0938\u0947 \u092c\u0928\u093e\u092f\u093e \u092f\u093e \u0928\u0937\u094d\u091f \u0928\u0939\u0940\u0902 \u0915\u093f\u092f\u093e \u091c\u093e \u0938\u0915\u0924\u093e\u0964 \u0938\u092d\u0940 \u092a\u0926\u093e\u0930\u094d\u0925 \u092a\u0930\u092e\u093e\u0923\u0941\u0913\u0902 \u0938\u0947 \u092c\u0928\u0947\u0964 \u090f\u0915 \u0924\u0924\u094d\u0935 \u0915\u0947 \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u092e\u093e\u0928 \u0926\u0942\u0938\u0930\u0947 \u0924\u0924\u094d\u0935 \u0938\u0947 \u092d\u093f\u0928\u094d\u0928\u0964 \u092f\u094c\u0917\u093f\u0915 \u092c\u0928\u0924\u0947 \u0938\u092e\u092f \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0930\u0932 \u092a\u0942\u0930\u094d\u0923 \u0938\u0902\u0916\u094d\u092f\u093e \u0905\u0928\u0941\u092a\u093e\u0924 \u092e\u0947\u0902 \u092e\u093f\u0932\u0924\u0947\u0964<br>\n<b>\u0938\u0940\u092e\u093e:<\/b> \u0909\u092a-\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0923 electron proton neutron \u0915\u0940 \u0935\u094d\u092f\u093e\u0916\u094d\u092f\u093e \u0928\u0939\u0940\u0902 \u0915\u0930 \u092a\u093e\u092f\u093e\u0964<br><br>\n\n<b>2. Thomson \u092e\u0949\u0921\u0932 1904 - Plum Pudding Model:<\/b><br>\n<b>\u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924:<\/b> J.J. Thomson \u0928\u0947 electron \u0916\u094b\u091c\u093e \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924\u0964 \u092a\u0930\u092e\u093e\u0923\u0941 \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0917\u094b\u0932\u093e \u091c\u093f\u0938\u092e\u0947\u0902 \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924 electrons \u0927\u0902\u0938\u0947 \u0939\u0941\u090f \u091c\u0948\u0938\u0947 \u0916\u0940\u0930 \u092e\u0947\u0902 \u0915\u093f\u0936\u092e\u093f\u0936 \u092f\u093e \u0924\u0930\u092c\u0942\u091c \u092e\u0947\u0902 \u092c\u0940\u091c\u0964 \u0915\u0941\u0932 \u0906\u0935\u0947\u0936 \u0909\u0926\u093e\u0938\u0940\u0928 \u0927\u0928 = \u090b\u0923\u0964<br>\n<b>\u0938\u0940\u092e\u093e:<\/b> Rutherford \u0915\u0947 Gold foil \u092a\u094d\u0930\u092f\u094b\u0917 \u0915\u094b \u0938\u092e\u091d\u093e \u0928\u0939\u0940\u0902 \u092a\u093e\u092f\u093e, \u0928\u093e\u092d\u093f\u0915 \u0915\u0940 \u0935\u094d\u092f\u093e\u0916\u094d\u092f\u093e \u0928\u0939\u0940\u0902\u0964<br><br>\n\n<b>3. Rutherford \u092e\u0949\u0921\u0932 1911 - Gold Foil Experiment:<\/b><br>\n<b>\u092a\u094d\u0930\u092f\u094b\u0917:<\/b> Alpha \u0915\u0923 (He\u00b2\u207a \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924) \u0938\u094b\u0928\u0947 \u0915\u0940 \u092a\u0928\u094d\u0928\u0940 \u092a\u0930 \u092e\u093e\u0930\u0947 - \u0905\u0927\u093f\u0915\u093e\u0902\u0936 \u0938\u0940\u0927\u0947 \u0928\u093f\u0915\u0932 \u0917\u090f, \u0915\u0941\u091b \u0925\u094b\u0921\u093c\u093e \u0935\u093f\u091a\u0932\u093f\u0924, \u092c\u0939\u0941\u0924 \u0915\u092e 1\/20000 \u0935\u093e\u092a\u0938 \u0932\u094c\u091f\u0947\u0964<br>\n<b>\u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924:<\/b> \u092a\u0930\u092e\u093e\u0923\u0941 \u0905\u0927\u093f\u0915\u093e\u0902\u0936 \u0916\u093e\u0932\u0940 \u091c\u0917\u0939, \u0918\u0928\u093e \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0928\u093e\u092d\u093f\u0915 \u0915\u0947\u0902\u0926\u094d\u0930 \u092e\u0947\u0902 \u091b\u094b\u091f\u093e \u0906\u0915\u093e\u0930 (\u0924\u094d\u0930\u093f\u091c\u094d\u092f\u093e \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u093e 1\/100000), electrons \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 \u092a\u0930\u093f\u0915\u094d\u0930\u092e\u093e \u0915\u0930\u0924\u0947\u0964<br>\n<b>\u0938\u0940\u092e\u093e:<\/b> Maxwell \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924 \u0905\u0928\u0941\u0938\u093e\u0930 \u092a\u0930\u093f\u0915\u094d\u0930\u092e\u093e \u0915\u0930\u0924\u093e electron \u090a\u0930\u094d\u091c\u093e \u0916\u094b\u0915\u0930 \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u0917\u093f\u0930 \u091c\u093e\u0928\u093e \u091a\u093e\u0939\u093f\u090f \u0932\u0947\u0915\u093f\u0928 \u0917\u093f\u0930\u0924\u093e \u0928\u0939\u0940\u0902 - \u0938\u094d\u0925\u093f\u0930\u0924\u093e \u0915\u0940 \u0935\u094d\u092f\u093e\u0916\u094d\u092f\u093e \u0928\u0939\u0940\u0902\u0964 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 \u0928\u0939\u0940\u0902 \u092c\u0924\u093e\u090f\u0964<br><br>\n\n<b>4. Bohr \u092e\u0949\u0921\u0932 1913 - Niels Bohr:<\/b><br>\n<b>\u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924:<\/b> Electrons \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 Orbits Shells K L M N \u092e\u0947\u0902 \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 \u0918\u0942\u092e\u0924\u0947\u0964 \u092a\u094d\u0930\u0924\u094d\u092f\u0947\u0915 orbit \u0915\u0940 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e\u0964 K \u0938\u092c\u0938\u0947 \u0915\u092e \u090a\u0930\u094d\u091c\u093e \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u0928\u093f\u0915\u091f\u0924\u092e\u0964 Electron \u091c\u092c \u090f\u0915 orbit \u0938\u0947 \u0926\u0942\u0938\u0930\u0947 \u092e\u0947\u0902 \u091c\u093e\u0924\u093e \u0924\u092d\u0940 \u090a\u0930\u094d\u091c\u093e \u0905\u0935\u0936\u094b\u0937\u0923\/\u0909\u0924\u094d\u0938\u0930\u094d\u091c\u0928\u0964<br>\n<b>\u092e\u0939\u0924\u094d\u0935:<\/b> Rutherford \u0915\u0940 \u0915\u092e\u0940 \u0926\u0942\u0930 \u0915\u0940 - \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u092e\u0947\u0902 electron \u090a\u0930\u094d\u091c\u093e \u0928\u0939\u0940\u0902 \u0916\u094b\u0924\u093e \u0907\u0938\u0932\u093f\u090f \u0938\u094d\u0925\u093f\u0930\u0964<br><br>\n\n<b>5. Modern Quantum Mechanical Model:<\/b><br>\n<b>\u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924:<\/b> \u0905\u092d\u0940 \u092d\u0940 \u0916\u094b\u091c \u091c\u093e\u0930\u0940 - electrons \u0915\u0940 \u0938\u094d\u0925\u093f\u0924\u093f \u0928\u093f\u0936\u094d\u091a\u093f\u0924 orbit \u0928\u0939\u0940\u0902 \u092c\u0932\u094d\u0915\u093f \u0938\u0902\u092d\u093e\u0935\u0928\u093e \u092e\u0947\u0918 Electron Cloud - Orbital \u092e\u0947\u0902 \u092a\u093e\u090f \u091c\u093e\u0928\u0947 \u0915\u0940 \u0938\u0902\u092d\u093e\u0935\u0928\u093e\u0964<br><br>\n\n<b>\u0915\u094d\u0930\u092e \u091f\u094d\u0930\u093f\u0915 \u0905\u0917\u094d\u0928\u093f\u0935\u0940\u0930: Dalton Indivisible \u2192 Thomson Plum Pudding \u2192 Rutherford Nucleus Dense \u2192 Bohr Fixed Energy \u2192 Modern Quantum - Still being discovered<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"d8-2\" style=\"display:none;\"><div style=\"background:#1565c0;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd35 \u092d\u093e\u0917 2\/5 - \u0909\u092a-\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0923 \u0914\u0930 \u0915\u094b\u0936<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>\u0909\u092a-\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0923 - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\n<b>1. Electron e\u207b - J.J. Thomson 1897 Cathode Ray Experiment:<\/b><br>\n- \u0906\u0935\u0947\u0936: -1.6\u00d710\u207b\u00b9\u2079 C \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924<br>\n- \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928: 9.1\u00d710\u207b\u00b3\u00b9 kg \u0932\u0917\u092d\u0917 1\/1837 proton \u0915\u093e<br>\n- \u0938\u094d\u0925\u093e\u0928: \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u092c\u093e\u0939\u0930 \u0915\u094b\u0936\u094b\u0902 K L M N \u092e\u0947\u0902 \u092a\u0930\u093f\u0915\u094d\u0930\u092e\u093e<br>\n- \u0916\u094b\u091c: Cathode ray tube \u092e\u0947\u0902<br><br>\n\n<b>2. Proton p\u207a - Goldstein 1886 Canal Ray, \u0928\u093e\u092e Rutherford 1919:<\/b><br>\n- \u0906\u0935\u0947\u0936: +1.6\u00d710\u207b\u00b9\u2079 C \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924<br>\n- \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928: 1.67\u00d710\u207b\u00b2\u2077 kg \u0932\u0917\u092d\u0917 1 u<br>\n- \u0938\u094d\u0925\u093e\u0928: \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902<br>\n- \u092a\u094d\u0930\u094b\u091f\u0949\u0928\u094b\u0902 \u0915\u0940 \u0938\u0902\u0916\u094d\u092f\u093e = \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e Z - \u0924\u0924\u094d\u0935 \u0915\u0940 \u092a\u0939\u091a\u093e\u0928<br><br>\n\n<b>3. Neutron n\u2070 - James Chadwick 1932:<\/b><br>\n- \u0906\u0935\u0947\u0936: 0 \u0909\u0926\u093e\u0938\u0940\u0928<br>\n- \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928: 1.67\u00d710\u207b\u00b2\u2077 kg proton \u0915\u0947 \u0932\u0917\u092d\u0917 \u092c\u0930\u093e\u092c\u0930 1 u<br>\n- \u0938\u094d\u0925\u093e\u0928: \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 proton \u0915\u0947 \u0938\u093e\u0925<br>\n- \u0915\u093e\u0930\u094d\u092f: \u0928\u093e\u092d\u093f\u0915 \u0915\u094b \u0938\u094d\u0925\u093f\u0930 \u0930\u0916\u0928\u093e proton-proton \u092a\u094d\u0930\u0924\u093f\u0915\u0930\u094d\u0937\u0923 \u0915\u092e \u0915\u0930\u0928\u093e<br><br>\n\n<b>\u0924\u0940\u0928\u094b\u0902 \u092e\u0942\u0932 \u0915\u0923 - \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0947 building blocks\u0964<\/b><br><br>\n\n<b>\u0915\u094b\u0936 Shell \/ Energy Level - K L M N - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0915\u0947 \u092a\u0925 \u091c\u0939\u093e\u0901 electron \u0918\u0942\u092e\u0924\u0947 \u0939\u0948\u0902\u0964 Bohr \u0928\u0947 \u0926\u093f\u090f\u0964<br>\n- K: \u092a\u0939\u0932\u093e \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u0928\u093f\u0915\u091f\u0924\u092e n=1 \u0905\u0927\u093f\u0915\u0924\u092e electrons 2, \u0928\u094d\u092f\u0942\u0928\u0924\u092e \u090a\u0930\u094d\u091c\u093e<br>\n- L: \u0926\u0942\u0938\u0930\u093e n=2 \u0905\u0927\u093f\u0915\u0924\u092e 8<br>\n- M: \u0924\u0940\u0938\u0930\u093e n=3 \u0905\u0927\u093f\u0915\u0924\u092e 18 \u0932\u0947\u0915\u093f\u0928 \u092c\u093e\u0939\u0930\u0940 \u0915\u094b\u0936 \u092e\u0947\u0902 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902 (Octet \u0928\u093f\u092f\u092e)<br>\n- N: \u091a\u094c\u0925\u093e n=4 \u0905\u0927\u093f\u0915\u0924\u092e 32 \u0932\u0947\u0915\u093f\u0928 \u092c\u093e\u0939\u0930\u0940 \u092e\u0947\u0902 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902<br><br>\n\n<b>\u0938\u0942\u0924\u094d\u0930: \u0915\u093f\u0938\u0940 \u0915\u094b\u0936 \u092e\u0947\u0902 \u0905\u0927\u093f\u0915\u0924\u092e electrons = 2n\u00b2<\/b><br>\nK n=1 \u21922\u00d71=2, L n=2 \u21922\u00d74=8, M n=3 \u21922\u00d79=18, N n=4 \u21922\u00d716=32<br><br>\n\n<b>\u0907\u0932\u0947\u0915\u094d\u091f\u094d\u0930\u0949\u0928\u093f\u0915 \u0935\u093f\u0928\u094d\u092f\u093e\u0938 Electronic Configuration - \u0928\u093f\u092f\u092e:<\/b><br>\n- \u092a\u0939\u0932\u0947 K \u092d\u0930\u0924\u093e \u092b\u093f\u0930 L \u092b\u093f\u0930 M<br>\n- \u092c\u093e\u0939\u0930\u0940 \u0915\u094b\u0936 \u092e\u0947\u0902 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902 \u0939\u094b\u0924\u0947 \u091c\u092c \u0924\u0915 \u0905\u0902\u0926\u0930 \u0935\u093e\u0932\u093e \u092a\u0942\u0930\u093e \u0928 \u0939\u094b (\u0915\u0941\u091b \u0905\u092a\u0935\u093e\u0926)<br>\n\u0909\u0926\u093e\u0939\u0930\u0923:<br>\nHydrogen Z1 \u21921 \u2192K1 \u21921<br>\nHelium Z2 \u21922 \u2192K2<br>\nLithium Z3 \u21922,1 \u2192K2 L1<br>\nBeryllium Z4 \u21922,2<br>\nBoron Z5 \u21922,3<br>\nCarbon Z6 \u21922,4<br>\nNitrogen Z7 \u21922,5<br>\nOxygen Z8 \u21922,6<br>\nFluorine Z9 \u21922,7<br>\nNeon Z10 \u21922,8 \u0938\u094d\u0925\u093f\u0930<br>\nSodium Z11 \u21922,8,1<br>\nMagnesium Z12 \u21922,8,2<br>\nAluminium Z13 \u21922,8,3<br>\nSilicon Z14 \u21922,8,4<br>\nPhosphorus Z15 \u21922,8,5<br>\nSulfur Z16 \u21922,8,6<br>\nChlorine Z17 \u21922,8,7<br>\nArgon Z18 \u21922,8,8 \u0938\u094d\u0925\u093f\u0930<br>\nPotassium Z19 \u21922,8,8,1<br>\nCalcium Z20 \u21922,8,8,2<br>\n\n<\/div><\/div>\n\n<div id=\"d8-3\" style=\"display:none;\"><div style=\"background:#2e7d32;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe2 \u092d\u093e\u0917 3\/5 - \u0938\u094d\u0925\u093f\u0930\u0924\u093e \u0914\u0930 \u0938\u0902\u092f\u094b\u091c\u0915\u0924\u093e<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>\u0938\u094d\u0925\u093f\u0930\u0924\u093e Stability - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u092c\u093e\u0939\u0930\u0940 \u0915\u094b\u0936 \u092e\u0947\u0902 Octet 8 electrons (\u092f\u0926\u093f K \u0939\u0940 \u092c\u093e\u0939\u0930\u0940 \u0924\u094b Duplet 2 electrons) \u0939\u094b \u0924\u094b \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u094d\u0925\u093f\u0930 Largely Unreactive - Noble gases\u0964<br>\n- He Z2 \u21922 \u2192K2 duplet \u0938\u094d\u0925\u093f\u0930<br>\n- Ne Z10 \u21922,8 octet \u0938\u094d\u0925\u093f\u0930<br>\n- Ar Z18 \u21922,8,8 octet \u0938\u094d\u0925\u093f\u0930<br>\n- Kr Xe Rn \u092d\u0940 \u0938\u094d\u0925\u093f\u0930<br><br>\n\n\u092f\u0926\u093f \u092c\u093e\u0939\u0930\u0940 \u092e\u0947\u0902 8 \u0938\u0947 \u0915\u092e \u0924\u094b \u092a\u0930\u092e\u093e\u0923\u0941 \u0905\u0938\u094d\u0925\u093f\u0930 - \u0938\u094d\u0925\u093f\u0930 \u0939\u094b\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f \u0907\u0932\u0947\u0915\u094d\u091f\u094d\u0930\u0949\u0928 \u0916\u094b\u0915\u0930 \u092a\u093e\u0915\u0930 \u092f\u093e \u0938\u093e\u091d\u093e \u0915\u0930\u0915\u0947 octet \u092a\u094d\u0930\u093e\u092a\u094d\u0924 \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094b\u0936\u093f\u0936 - \u0907\u0938\u0940 \u0938\u0947 Chemical Bond \u092c\u0928\u0924\u093e - Chapter 9 \u092e\u0947\u0902 \u0935\u093f\u0938\u094d\u0924\u093e\u0930\u0964<br><br>\n\n<b>\u0938\u0902\u092f\u094b\u091c\u0915\u0924\u093e Valency - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0940 \u0938\u0902\u092f\u094b\u091c\u0928 \u0915\u094d\u0937\u092e\u0924\u093e - \u0938\u094d\u0925\u093f\u0930 \u0935\u093f\u0928\u094d\u092f\u093e\u0938 \u092a\u094d\u0930\u093e\u092a\u094d\u0924 \u0915\u0930\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f \u091c\u093f\u0924\u0928\u0947 electrons \u0916\u094b\u090f \u092a\u093e\u090f \u092f\u093e \u0938\u093e\u091d\u093e \u0915\u093f\u090f \u091c\u093e\u0924\u0947 \u0939\u0948\u0902 \u0935\u0939 \u0938\u0902\u0916\u094d\u092f\u093e\u0964<br><br>\n\n<b>\u0938\u0942\u0924\u094d\u0930 Valency \u0928\u093f\u0915\u093e\u0932\u0928\u0947 \u0915\u093e:<\/b><br>\n- \u092f\u0926\u093f \u092c\u093e\u0939\u0930\u0940 electrons 1-4 \u2192 Valency = \u092c\u093e\u0939\u0930\u0940 electrons \u0938\u0902\u0916\u094d\u092f\u093e (\u0926\u0947\u0928\u0947 \u0915\u0940 \u092a\u094d\u0930\u0935\u0943\u0924\u094d\u0924\u093f)<br>\n- \u092f\u0926\u093f \u092c\u093e\u0939\u0930\u0940 5-7 \u2192 Valency = 8 - \u092c\u093e\u0939\u0930\u0940 electrons \u0938\u0902\u0916\u094d\u092f\u093e (\u0932\u0947\u0928\u0947 \u0915\u0940 \u092a\u094d\u0930\u0935\u0943\u0924\u094d\u0924\u093f)<br>\n- \u092c\u093e\u0939\u0930\u0940 4 \u2192 4 (\u0926\u0947\u0928\u093e \u0932\u0947\u0928\u093e \u0926\u094b\u0928\u094b\u0902 \u0915\u0920\u093f\u0928 \u0938\u093e\u091d\u093e)<br>\n- \u092c\u093e\u0939\u0930\u0940 8 \u2192 0 \u0938\u094d\u0925\u093f\u0930<br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923:<\/b><br>\nLi 2,1 \u2192 \u092c\u093e\u0939\u0930\u0940 1 \u2192Valency 1 \u0926\u0947\u0928\u093e<br>\nBe 2,2 \u21922 \u0926\u0947\u0928\u093e Valency 2<br>\nB 2,3 \u21923 \u0926\u0947\u0928\u093e Valency 3<br>\nC 2,4 \u21924 Valency 4 \u0938\u093e\u091d\u093e<br>\nN 2,5 \u21928-5=3 \u0932\u0947\u0928\u093e Valency 3<br>\nO 2,6 \u21928-6=2 Valency 2<br>\nF 2,7 \u21928-7=1 Valency 1<br>\nNe 2,8 \u21920 Valency 0<br>\nNa 2,8,1 \u21921 Valency 1<br>\nMg 2,8,2 \u21922 Valency 2<br>\nAl 2,8,3 \u21923 Valency 3<br>\nSi 2,8,4 \u21924 Valency 4<br>\nP 2,8,5 \u21923 Valency 3<br>\nS 2,8,6 \u21922 Valency 2<br>\nCl 2,8,7 \u21921 Valency 1<br>\nAr 2,8,8 \u21920 Valency 0<br><br>\n\n<b>Fig 8.17 Q9 Answer Key \u092a\u0947\u091c 272 \u0938\u0947:<\/b><br>\n(a) Lithium Li - Total 3 electrons - Valence 1 - Valency 1 - Protons 3 - Atomic number 3<br>\n(b) Nitrogen N - Total 7 - Valence 5 - Valency 3 - Protons 7 - Atomic 7<br>\n(c) Aluminium Al - Total 13 - Valence 3 - Valency 3 - Protons 13 - Atomic 13<br>\n(d) Fluorine F - Total 9 - Valence 7 - Valency 1 - Protons 9 - Atomic 9<br>\n\n<\/div><\/div>\n\n<div id=\"d8-4\" style=\"display:none;\"><div style=\"background:#4a148c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe3 \u092d\u093e\u0917 4\/5 - \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0938\u0902\u0916\u094d\u092f\u093e<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>\u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e Atomic Number Z - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u092a\u094d\u0930\u094b\u091f\u0949\u0928\u094b\u0902 \u0915\u0940 \u0938\u0902\u0916\u094d\u092f\u093e - \u0915\u093f\u0938\u0940 \u0924\u0924\u094d\u0935 \u0915\u0940 \u092a\u0939\u091a\u093e\u0928 - \u090f\u0915 \u0939\u0940 \u0924\u0924\u094d\u0935 \u0915\u0947 \u0938\u092d\u0940 \u092a\u0930\u092e\u093e\u0923\u0941\u0913\u0902 \u092e\u0947\u0902 Z \u0938\u092e\u093e\u0928\u0964<br>\n<b>\u0938\u0942\u0924\u094d\u0930:<\/b> Z = Number of Protons = Number of Electrons (\u0909\u0926\u093e\u0938\u0940\u0928 \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0947\u0902)<br>\n\u0909\u0926\u093e\u0939\u0930\u0923: Sodium Z11 \u2192Protons 11 Electrons 11, Chlorine Z17 \u2192P17 E17<br><br>\n\n<b>\u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0938\u0902\u0916\u094d\u092f\u093e Mass Number A - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u0915\u0941\u0932 Nucleons (Protons + Neutrons) \u0915\u0940 \u0938\u0902\u0916\u094d\u092f\u093e\u0964<br>\n<b>\u0938\u0942\u0924\u094d\u0930: A = Protons + Neutrons = Z + n<\/b><br>\n<b>Neutrons = A - Z<\/b><br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 - Example Q8 \u092a\u0947\u091c 159 Magnesium Mass 24 Atomic 12:<\/b><br>\nProtons = Z =12, Electrons =12 (\u0909\u0926\u093e\u0938\u0940\u0928), Neutrons = A-Z =24-12=12, Configuration 2,8,2 K2 L8 M2<br><br>\n\n<b>\u0905\u0928\u094d\u092f \u0909\u0926\u093e\u0939\u0930\u0923 Answer Key \u0938\u0947:<\/b><br>\n- Iron Fe: Electrons 26 Protons 26 Neutrons 30 \u2192Z26 A56 (26+30) Configuration 2,8,14,2<br>\n- Chlorine Cl: Mass 35 Atomic 17 \u2192P17 E17 N18 (35-17) Configuration 2,8,7 Valency1<br>\n- Boron B: Z5 A11 \u2192P5 E5 N6 (11-5) 2,3<br>\n- Nitrogen N: Z7 A14 \u2192P7 E7 N7 2,5<br>\n- Phosphorus P: Z15 A31 \u2192P15 E15 N16 2,8,5<br>\n- Hydrogen H: Z1 A1 \u2192P1 E1 N0 1<br><br>\n\n<b>Average Atomic Mass \u0914\u0938\u0924 \u092a\u0930\u092e\u093e\u0923\u0941 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u0924\u0924\u094d\u0935 \u0915\u0947 \u0938\u092e\u0938\u094d\u0925\u093e\u0928\u093f\u0915\u094b\u0902 \u0915\u0940 \u092a\u094d\u0930\u0915\u0943\u0924\u093f \u092e\u0947\u0902 \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u092c\u0939\u0941\u0932\u0924\u093e Relative Abundance \u0915\u0947 \u0906\u0927\u093e\u0930 \u092a\u0930 \u0914\u0938\u0924 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928\u0964<br>\n<b>\u0938\u0942\u0924\u094d\u0930: Average = (Mass1\u00d7%1 + Mass2\u00d7%2 + ...)\/100<\/b><br>\n\u0909\u0926\u093e\u0939\u0930\u0923: Chlorine \u0926\u094b isotope \u00b3\u2075Cl 75% \u0914\u0930 \u00b3\u2077Cl 25% \u2192Average = (35\u00d775 + 37\u00d725)\/100 = (2625+925)\/100=3550\/100=35.5 u<br>\nBoron \u00b9\u2070B 20% \u00b9\u00b9B 80% \u2192(10\u00d720+11\u00d780)\/100=10.8 u \u0932\u0917\u092d\u0917 10.81<br>\nBromine \u2077\u2079Br \u2078\u00b9Br \u0914\u0938\u0924 79.9 \u219280.006 u \u0932\u0917\u092d\u0917<br><br>\n\n<b>\u092a\u094d\u0930\u0924\u0940\u0915 Notation: \u1d2cX_Z - \u091c\u0948\u0938\u0947 \u00b9\u00b2C\u2086, \u00b3\u2075Cl\u2081\u2087, \u00b2\u2074Mg\u2081\u2082, \u00b2\u2077Al\u2081\u2083 - \u090a\u092a\u0930 A \u0928\u0940\u091a\u0947 Z \u092c\u0940\u091a \u092e\u0947\u0902 \u0924\u0924\u094d\u0935 \u092a\u094d\u0930\u0924\u0940\u0915\u0964<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"d8-5\" style=\"display:none;\"><div style=\"background:#004d40;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\u2705 \u092d\u093e\u0917 5\/5 - \u0938\u092e\u0938\u094d\u0925\u093e\u0928\u093f\u0915 \u0938\u092e\u092d\u093e\u0930\u093f\u0915 \u0914\u0930 \u0938\u093e\u0930<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Isotopes \u0938\u092e\u0938\u094d\u0925\u093e\u0928\u093f\u0915 - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u090f\u0915 \u0939\u0940 \u0924\u0924\u094d\u0935 \u0915\u0947 \u092a\u0930\u092e\u093e\u0923\u0941 \u091c\u093f\u0928\u0915\u0940 \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e Z \u0938\u092e\u093e\u0928 \u0932\u0947\u0915\u093f\u0928 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0938\u0902\u0916\u094d\u092f\u093e A \u092d\u093f\u0928\u094d\u0928 - \u092a\u094d\u0930\u094b\u091f\u0949\u0928 \u0938\u092e\u093e\u0928 \u0928\u094d\u092f\u0942\u091f\u094d\u0930\u0949\u0928 \u092d\u093f\u0928\u094d\u0928\u0964<br>\n<b>\u0938\u0942\u0924\u094d\u0930: Z \u0938\u092e\u093e\u0928 A \u092d\u093f\u0928\u094d\u0928 \u2192p \u0938\u092e\u093e\u0928 n \u092d\u093f\u0928\u094d\u0928<\/b><br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923:<\/b><br>\n- Hydrogen: Protium \u00b9H\u2081 p1 n0, Deuterium \u00b2H\u2081 p1 n1 \u092d\u093e\u0930\u0940 \u091c\u0932, Tritium \u00b3H\u2081 p1 n2 \u0930\u0947\u0921\u093f\u092f\u094b\u0927\u0930\u094d\u092e\u0940<br>\n- Carbon: \u00b9\u00b2C 6p6n 98.9% \u0914\u0930 \u00b9\u2074C 6p8n 0.1% \u0930\u0947\u0921\u093f\u092f\u094b\u0927\u0930\u094d\u092e\u0940 dating \u092e\u0947\u0902<br>\n- Chlorine: \u00b3\u2075Cl 17p18n 75% \u0914\u0930 \u00b3\u2077Cl 17p20n 25%<br>\n- Oxygen: \u00b9\u2076O 8p8n, \u00b9\u2077O 8p9n, \u00b9\u2078O 8p10n<br>\n- Uranium: \u00b2\u00b3\u2075U 92p143n \u0914\u0930 \u00b2\u00b3\u2078U 92p146n<br><br>\n\n<b>\u0917\u0941\u0923:<\/b> \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u0917\u0941\u0923 \u0938\u092e\u093e\u0928 (electron \u0938\u092e\u093e\u0928 Z \u0938\u092e\u093e\u0928) \u092d\u094c\u0924\u093f\u0915 \u0917\u0941\u0923 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0915\u0947 \u0915\u093e\u0930\u0923 \u0925\u094b\u0921\u093c\u0947 \u092d\u093f\u0928\u094d\u0928 \u0918\u0928\u0924\u094d\u0935 \u0915\u094d\u0935\u0925\u0928\u093e\u0902\u0915\u0964<br><br>\n\n<b>\u0909\u092a\u092f\u094b\u0917 - \u0905\u0917\u094d\u0928\u093f\u0935\u0940\u0930 \u0915\u0947 \u0932\u093f\u090f \u092e\u0939\u0924\u094d\u0935\u092a\u0942\u0930\u094d\u0923:<\/b><br>\n- U-235 Nuclear fuel \u092c\u093f\u091c\u0932\u0940 \u0909\u0924\u094d\u092a\u093e\u0926\u0928<br>\n- Co-60 Cobalt 60 Cancer treatment<br>\n- I-131 Iodine 131 Thyroid treatment<br>\n- C-14 Carbon 14 Fossil dating \u091c\u0940\u0935\u093e\u0936\u094d\u092e \u0906\u092f\u0941<br>\n- Na-24 Sodium 24 Blood clot<br><br>\n\n<b>Isobars \u0938\u092e\u092d\u093e\u0930\u093f\u0915 - \u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b><br>\n\u0935\u093f\u092d\u093f\u0928\u094d\u0928 \u0924\u0924\u094d\u0935\u094b\u0902 \u0915\u0947 \u092a\u0930\u092e\u093e\u0923\u0941 \u091c\u093f\u0928\u0915\u0940 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0938\u0902\u0916\u094d\u092f\u093e A \u0938\u092e\u093e\u0928 \u0932\u0947\u0915\u093f\u0928 \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0916\u094d\u092f\u093e Z \u092d\u093f\u0928\u094d\u0928\u0964<br>\n<b>\u0938\u0942\u0924\u094d\u0930: A \u0938\u092e\u093e\u0928 Z \u092d\u093f\u0928\u094d\u0928 \u2192p \u092d\u093f\u0928\u094d\u0928 n \u092d\u093f\u0928\u094d\u0928 \u0932\u0947\u0915\u093f\u0928 p+n \u0938\u092e\u093e\u0928<\/b><br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923:<\/b><br>\n- Argon \u2074\u2070Ar\u2081\u2088 18p22n \u0914\u0930 Calcium \u2074\u2070Ca\u2082\u2080 20p20n \u2192A40 \u0926\u094b\u0928\u094b\u0902 Z18 \u0914\u0930 Z20 \u092d\u093f\u0928\u094d\u0928<br>\n- Carbon \u00b9\u2074C\u2086 6p8n \u0914\u0930 Nitrogen \u00b9\u2074N\u2087 7p7n \u2192A14 \u0938\u092e\u093e\u0928 Z6 Z7 \u092d\u093f\u0928\u094d\u0928<br><br>\n\n<b>\u0917\u0941\u0923:<\/b> \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u0917\u0941\u0923 \u092d\u093f\u0928\u094d\u0928 (electron \u092d\u093f\u0928\u094d\u0928 Z \u092d\u093f\u0928\u094d\u0928) \u092d\u094c\u0924\u093f\u0915 \u0917\u0941\u0923 \u0915\u0941\u091b \u0938\u092e\u093e\u0928 \u0939\u094b \u0938\u0915\u0924\u0947\u0964<br><br>\n\n<div style=\"background:#ede7f6;border-left:4px solid #4a148c;padding:8px 10px;font-weight:bold;\">At a Glance \u092a\u0947\u091c 157 - \u0938\u093e\u0930 PDF \u0938\u0947 \u0936\u0941\u0926\u094d\u0927:<\/div>\n- Atoms building blocks of matter\u0964<br>\n- Thomson electrons embedded positively charged sphere\u0964<br>\n- Rutherford mostly empty dense positively charged nucleus centre electrons orbiting\u0964<br>\n- Bohr fixed energy levels shells K L M N\u0964<br>\n- Chadwick discovered neutrons\u0964<br>\n- Three subatomic electrons protons neutrons\u0964<br>\n- Outermost octet (He 2) stable unreactive\u0964<br>\n- Valency combining capacity electrons gained lost shared\u0964<br>\n- Atomic number protons in nucleus\u0964<br>\n- Mass number total nucleons protons+neutrons\u0964<br>\n- Isotopes same Z different A\u0964<br>\n- Average atomic mass relative abundance isotopes\u0964<br>\n- Isobars different Z same A\u0964<br><br>\n\n<div style=\"background:#fff9c4;border:3px solid #fbc02d;padding:10px;border-radius:10px;text-align:center;font-weight:bold;\">\n\u2705 Chapter 8 \u092d\u093e\u0917 2 \u092a\u0930\u093f\u092d\u093e\u0937\u093e \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924 \u0938\u0942\u0924\u094d\u0930 \u0936\u0941\u0926\u094d\u0927 \u0916\u0924\u094d\u092e<br>\nModel \u0915\u094d\u0930\u092e Dalton Indivisible \u2192Thomson Plum Pudding \u2192Rutherford Nucleus Dense Gold foil \u2192Bohr KLMN Fixed Energy \u2192Modern Quantum Cloud<br>\nSubatomic e\u207b Thomson -1.6\u00d710\u207b\u00b9\u2079 9.1\u00d710\u207b\u00b3\u00b9 KLMN \u092e\u0947\u0902, p\u207a Goldstein +1.6\u00d710\u207b\u00b9\u2079 1.67\u00d710\u207b\u00b2\u2077 \u0928\u093e\u092d\u093f\u0915 Z, n\u2070 Chadwick 0 1.67\u00d710\u207b\u00b2\u2077 \u0928\u093e\u092d\u093f\u0915 \u0938\u094d\u0925\u093f\u0930\u0924\u093e<br>\nShell K L M N 2n\u00b2 K2 L8 M18 N32 \u092c\u093e\u0939\u0930\u0940 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902, Configuration Na 2,8,1 Mg 2,8,2 Al 2,8,3 Cl 2,8,7 Ar 2,8,8 \u0938\u094d\u0925\u093f\u0930 octet<br>\nValency \u092c\u093e\u0939\u0930\u0940 1-4=\u092c\u093e\u0939\u0930\u0940 5-7=8-\u092c\u093e\u0939\u0930\u0940 8=0 Li1 Be2 B3 C4 N3 O2 F1 Ne0 Na1 Mg2 Al3 Si4 P3 S2 Cl1 Ar0 - Li N Al F<br>\nZ=p=e \u0909\u0926\u093e\u0938\u0940\u0928 A=p+n n=A-Z Mg24 12 p12 e12 n12 2,8,2 Fe26 26 30 56 Cl35 17 17 18, Average (35\u00d775+37\u00d725)\/100=35.5 Br 80.006<br>\nIsotopes Z \u0938\u092e\u093e\u0928 A \u092d\u093f\u0928\u094d\u0928 p \u0938\u092e\u093e\u0928 n \u092d\u093f\u0928\u094d\u0928 H1 1 2 3 C12 14 Cl35 37 O16 17 18 U235 238 chemical same uses U235 fuel Co60 cancer I131 thyroid C14 dating, Isobars A \u0938\u092e\u093e\u0928 Z \u092d\u093f\u0928\u094d\u0928 Ar40 Ca40 C14 N14 chemical \u092d\u093f\u0928\u094d\u0928<br>\n\u0905\u0917\u0932\u093e \u092d\u093e\u0917 \u092a\u094d\u0930\u0936\u094d\u0928\u093e\u0935\u0932\u0940 \u0915\u094b\u0908 \u092a\u094d\u0930\u0936\u094d\u0928 \u0928\u0939\u0940\u0902 \u091b\u0942\u091f\u0947\u0917\u093e \u0935\u093e\u0932\u093e \u092c\u0928\u093e\u090a\u0901 \u0938\u0930?\n<\/div>\n\n<\/div><\/div>\n<\/div>\n\n<div style=\"background:#4a148c;padding:12px;display:flex;justify-content:space-between;align-items:center;\">\n<button type=\"button\" id=\"d8p\" style=\"background:#ffcc00;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">&larr; \u092a\u0940\u091b\u0947<\/button>\n<span id=\"d8i\" style=\"background:#fff;color:#4a148c;padding:8px 20px;border-radius:20px;font-weight:bold;\">1 \/ 5<\/span>\n<button type=\"button\" id=\"d8n\" style=\"background:#00e676;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">\u0906\u0917\u0947 &rarr;<\/button>\n<\/div>\n<\/div>\n\n<script>\n(function(){\nvar c=1,t=5;\nfunction s(n){\nfor(var i=1;i<=t;i++){\nvar el=document.getElementById('d8-'+i);\nif(el)el.style.display=(i===n?'block':'none');\n}\ndocument.getElementById('d8i').textContent=n+' \/ '+t;\nc=n;\n}\ndocument.getElementById('d8n').onclick=function(){var n=c+1;if(n>t)n=1;s(n);};\ndocument.getElementById('d8p').onclick=function(){var n=c-1;if(n<1)n=t;s(n);};\n})();\n<\/script><\/div><\/div><\/div><\/div><div id=\"pg-845-2\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-845-2-0\"  class=\"panel-grid-cell\" ><div id=\"panel-845-2-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"2\" ><div class=\"textwidget custom-html-widget\"><div id=\"CH8-EXER\" style=\"max-width:860px;margin:12px auto;border:4px solid #4a148c;border-radius:14px;background:#ede7f6;font-family:'Noto Sans Devanagari',Arial,sans-serif;overflow:hidden;\">\n<div style=\"background:#4a148c;padding:10px;text-align:center;\"><span style=\"background:#fff;color:#4a148c;padding:7px 20px;border-radius:20px;font-weight:bold;font-size:14px;\">Chapter 8 - \u0938\u093e\u0930\u0940 \u092a\u094d\u0930\u0936\u094d\u0928\u093e\u0935\u0932\u0940 - \u0915\u094b\u0908 \u092a\u094d\u0930\u0936\u094d\u0928 \u0928\u0939\u0940\u0902 \u091b\u0942\u091f\u093e - \u0936\u0941\u0926\u094d\u0927<\/span><\/div>\n\n<div style=\"padding:10px 12px;\">\n<div id=\"e8-1\" style=\"display:block;\"><div style=\"background:#b71c1c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd34 \u092d\u093e\u0917 1\/5 - Pause and Ponder Q1-Q7<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Pause and Ponder - PDF \u0938\u0947:<\/b><br>\n\n<b>Q1. Dalton \u0915\u0947 \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924 \u0915\u0947 \u0905\u0928\u0941\u0938\u093e\u0930 \u092a\u0930\u092e\u093e\u0923\u0941 \u0905\u0935\u093f\u092d\u093e\u091c\u094d\u092f \u0939\u0948\u0964 \u0915\u094d\u092f\u093e \u092f\u0939 \u0938\u0924\u094d\u092f \u0939\u0948? \u0906\u0927\u0941\u0928\u093f\u0915 \u0916\u094b\u091c\u094b\u0902 \u0915\u0947 \u0906\u0927\u093e\u0930 \u092a\u0930 \u0938\u092e\u091d\u093e\u090f\u0902\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0928\u0939\u0940\u0902, Dalton \u0915\u093e \u092f\u0939 \u0915\u0925\u0928 \u0906\u0902\u0936\u093f\u0915 \u0938\u0924\u094d\u092f \u0939\u0948\u0964 \u0906\u0927\u0941\u0928\u093f\u0915 \u0916\u094b\u091c\u094b\u0902 \u0928\u0947 \u092c\u0924\u093e\u092f\u093e \u092a\u0930\u092e\u093e\u0923\u0941 \u0935\u093f\u092d\u093e\u091c\u094d\u092f \u0939\u0948 - \u0905\u0902\u0926\u0930 \u0924\u0940\u0928 \u0909\u092a-\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0923 Electron Thomson, Proton Rutherford, Neutron Chadwick \u0939\u094b\u0924\u0947 \u0939\u0948\u0902\u0964 \u092a\u0930\u092e\u093e\u0923\u0941 \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u0905\u092d\u093f\u0915\u094d\u0930\u093f\u092f\u093e \u092e\u0947\u0902 \u0905\u0935\u093f\u092d\u093e\u091c\u094d\u092f \u0930\u0939\u0924\u093e \u0939\u0948 \u0932\u0947\u0915\u093f\u0928 \u0928\u093e\u092d\u093f\u0915\u0940\u092f \u0905\u092d\u093f\u0915\u094d\u0930\u093f\u092f\u093e \u092e\u0947\u0902 \u0935\u093f\u092d\u093e\u091c\u094d\u092f\u0964<\/b><br><br>\n\n<b>Q2. Thomson \u0915\u0947 \u092e\u0949\u0921\u0932 \u092e\u0947\u0902 \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u094b Plum Pudding \u0915\u094d\u092f\u094b\u0902 \u0915\u0939\u093e \u0917\u092f\u093e? \u0915\u092e\u0940 \u092c\u0924\u093e\u090f\u0902\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0917\u094b\u0932\u0947 \u092e\u0947\u0902 \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924 electrons \u0927\u0902\u0938\u0947 \u091c\u0948\u0938\u0947 \u0916\u0940\u0930 \u092e\u0947\u0902 \u0915\u093f\u0936\u092e\u093f\u0936 \u092f\u093e \u0924\u0930\u092c\u0942\u091c \u092e\u0947\u0902 \u092c\u0940\u091c - \u0907\u0938\u0932\u093f\u090f Plum Pudding\u0964 \u0915\u092e\u0940 - Gold foil \u092a\u094d\u0930\u092f\u094b\u0917 \u0915\u094b \u0938\u092e\u091d\u093e \u0928\u0939\u0940\u0902 \u092a\u093e\u092f\u093e, \u0928\u093e\u092d\u093f\u0915 \u0915\u0940 \u0935\u094d\u092f\u093e\u0916\u094d\u092f\u093e \u0928\u0939\u0940\u0902\u0964<\/b><br><br>\n\n<b>Q3. Rutherford \u0915\u0947 Gold Foil \u092a\u094d\u0930\u092f\u094b\u0917 \u0938\u0947 \u0915\u094d\u092f\u093e \u0928\u093f\u0937\u094d\u0915\u0930\u094d\u0937 \u0928\u093f\u0915\u0932\u0947?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (i) \u092a\u0930\u092e\u093e\u0923\u0941 \u0905\u0927\u093f\u0915\u093e\u0902\u0936 \u0916\u093e\u0932\u0940 (\u0905\u0927\u093f\u0915\u093e\u0902\u0936 Alpha \u0938\u0940\u0927\u0947 \u0928\u093f\u0915\u0932\u0947) (ii) \u0918\u0928\u093e \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0928\u093e\u092d\u093f\u0915 \u0915\u0947\u0902\u0926\u094d\u0930 \u092e\u0947\u0902 \u091b\u094b\u091f\u093e (\u0915\u0941\u091b Alpha \u0935\u093f\u091a\u0932\u093f\u0924 \u092c\u0939\u0941\u0924 \u0915\u092e \u0935\u093e\u092a\u0938) (iii) Electrons \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 \u092a\u0930\u093f\u0915\u094d\u0930\u092e\u093e (iv) \u0928\u093e\u092d\u093f\u0915 \u0924\u094d\u0930\u093f\u091c\u094d\u092f\u093e \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u093e 1\/100000\u0964<\/b><br><br>\n\n<b>Q4. Bohr \u092e\u0949\u0921\u0932 Rutherford \u0938\u0947 \u092c\u0947\u0939\u0924\u0930 \u0915\u094d\u092f\u094b\u0902?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Rutherford \u092e\u0947\u0902 electron \u090a\u0930\u094d\u091c\u093e \u0916\u094b\u0915\u0930 \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u0917\u093f\u0930\u0928\u093e \u091a\u093e\u0939\u093f\u090f \u0938\u094d\u0925\u093f\u0930\u0924\u093e \u0928\u0939\u0940\u0902\u0964 Bohr \u0928\u0947 \u092c\u0924\u093e\u092f\u093e electrons \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 K L M N \u092e\u0947\u0902 \u0918\u0942\u092e\u0924\u0947 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0928\u0939\u0940\u0902 \u0916\u094b\u0924\u0947 \u0907\u0938\u0932\u093f\u090f \u0938\u094d\u0925\u093f\u0930 - \u090a\u0930\u094d\u091c\u093e \u0905\u0935\u0936\u094b\u0937\u0923\/\u0909\u0924\u094d\u0938\u0930\u094d\u091c\u0928 \u0924\u092d\u0940 \u091c\u092c orbit \u092c\u0926\u0932\u0924\u093e\u0964<\/b><br><br>\n\n<b>Q5. \u0938\u0939\u0940 \u0915\u094d\u0930\u092e \u0932\u0917\u093e\u0913: (i) Bohr fixed orbits (ii) Thomson plum pudding (iii) Rutherford dense nucleus (iv) Dalton indivisible<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (iv) Dalton indivisible 1808 \u2192 (ii) Thomson plum pudding 1904 \u2192 (iii) Rutherford dense nucleus 1911 \u2192 (i) Bohr fixed orbits 1913\u0964 Answer Key \u092e\u0947\u0902 \u092f\u0939\u0940 \u0915\u094d\u0930\u092e\u0964<\/b><br><br>\n\n<b>Q6. Electrons \u0928\u093e\u092d\u093f\u0915 \u0915\u0947 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 orbits \u092e\u0947\u0902 \u0915\u094d\u092f\u094b\u0902 \u0928\u0939\u0940\u0902 \u0909\u0921\u093c \u091c\u093e\u0924\u0947? \u0915\u094d\u092f\u093e \u0906\u0915\u0930\u094d\u0937\u093f\u0924 \u0930\u0916\u0924\u093e?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0928\u093e\u092d\u093f\u0915 protons \u0914\u0930 \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924 electrons \u0915\u0947 \u092c\u0940\u091a \u0938\u094d\u0925\u093f\u0930\u0935\u0948\u0926\u094d\u092f\u0941\u0924 \u0906\u0915\u0930\u094d\u0937\u0923 Electrostatic attraction centripetal force \u0915\u0947 \u0930\u0942\u092a \u092e\u0947\u0902 - Bohr \u0915\u0947 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 \u092e\u0947\u0902 \u0918\u0942\u092e\u0924\u0947\u0964<\/b><br><br>\n\n<b>Q7. Assertion: \u0909\u092a-\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0923\u094b\u0902 \u0915\u0940 \u0916\u094b\u091c \u0928\u0947 \u092a\u0930\u092e\u093e\u0923\u0941 \u0938\u0902\u0930\u091a\u0928\u093e \u0938\u092e\u091d\u0928\u0947 \u092e\u0947\u0902 \u092e\u0926\u0926 \u0915\u0940 Reason: \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0947\u0902 electrons \u0938\u0902\u0916\u094d\u092f\u093e protons \u0915\u0947 \u092c\u0930\u093e\u092c\u0930 \u0939\u094b\u0924\u0940 \u0939\u0948\u0964 \u0938\u0939\u0940 \u0935\u093f\u0915\u0932\u094d\u092a?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (ii) \u0926\u094b\u0928\u094b\u0902 \u0938\u0924\u094d\u092f \u0932\u0947\u0915\u093f\u0928 R A \u0915\u0940 \u0938\u0939\u0940 \u0935\u094d\u092f\u093e\u0916\u094d\u092f\u093e \u0928\u0939\u0940\u0902 - \u0916\u094b\u091c \u0938\u0947 \u092e\u0949\u0921\u0932 \u092c\u0928\u093e electrons=protons \u0909\u0926\u093e\u0938\u0940\u0928\u0924\u093e \u0915\u093e \u092a\u0930\u093f\u0923\u093e\u092e \u0932\u0947\u0915\u093f\u0928 \u0915\u093e\u0930\u0923 \u0928\u0939\u0940\u0902\u0964 Answer Key (ii)\u0964<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"e8-2\" style=\"display:none;\"><div style=\"background:#1565c0;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd35 \u092d\u093e\u0917 2\/5 - Q8-Q14<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q8. Magnesium \u0915\u093e mass number 24 atomic number 12 \u0924\u094b (i) protons (ii) neutrons (iii) electrons \u0914\u0930 \u0935\u093f\u0928\u094d\u092f\u093e\u0938 \u092c\u0924\u093e\u0913\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Protons = Z=12, Electrons=12 \u0909\u0926\u093e\u0938\u0940\u0928, Neutrons = A-Z=24-12=12, Configuration 2,8,2 K2 L8 M2 - Answer Key Protons12 Neutrons12 Electrons12 2,8,2\u0964<\/b><br><br>\n\n<b>Q9. Fig 8.17 \u092e\u0947\u0902 \u091a\u093e\u0930 \u092a\u0930\u092e\u093e\u0923\u0941 \u0906\u0930\u0947\u0916 (a)(b)(c)(d) \u0926\u093f\u090f \u0939\u0948\u0902 - \u092a\u094d\u0930\u0924\u094d\u092f\u0947\u0915 \u0915\u0947 \u0932\u093f\u090f Total electrons, Valence electrons, Valency, Protons, Atomic number \u092c\u0924\u093e\u0913 - Answer Key \u092a\u0947\u091c 272 \u0938\u0947:<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (a) Lithium Li - Total 3 - Valence 1 - Valency 1 - Protons 3 - Atomic 3 - K2 L1 (b) Nitrogen N - Total 7 - Valence 5 - Valency 3 - Protons 7 - Atomic 7 - K2 L5 (c) Aluminium Al - Total 13 - Valence 3 - Valency 3 - Protons 13 - Atomic 13 - K2 L8 M3 (d) Fluorine F - Total 9 - Valence 7 - Valency 1 - Protons 9 - Atomic 9 - K2 L7\u0964<\/b><br><br>\n\n<b>Q10. \u090f\u0915 \u0924\u0924\u094d\u0935 \u092e\u0947\u0902 Electrons 26 Protons 26 Neutrons 30 - \u092a\u0939\u091a\u093e\u0928\u094b\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Z=26 Protons=26 \u2192Iron Fe, A=26+30=56 \u2192\u2075\u2076Fe\u2082\u2086, Configuration 2,8,14,2\u0964 Answer Key Electrons26 Protons26 Neutrons30\u0964<\/b><br><br>\n\n<b>Q11. Neutrons 21 \u0935\u093e\u0932\u093e \u0924\u0924\u094d\u0935 - \u0915\u094d\u092f\u093e \u092c\u0924\u093e \u0938\u0915\u0924\u0947?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u092f\u0926\u093f Z \u0926\u093f\u092f\u093e \u0939\u094b \u0924\u094b A \u0928\u093f\u0915\u093e\u0932\u0924\u0947 - \u0909\u0926\u093e\u0939\u0930\u0923 \u092f\u0926\u093f Z20 Calcium \u0924\u094b A=20+21=41 \u2192\u2074\u00b9Ca\u2082\u2080\u0964 Answer Key Neutrons21 - \u0938\u093e\u092e\u093e\u0928\u094d\u092f \u092a\u094d\u0930\u0936\u094d\u0928\u0964<\/b><br><br>\n\n<b>Q12. Mass number 35 \u0935\u093e\u0932\u093e \u0924\u0924\u094d\u0935 - \u092c\u0924\u093e\u0913\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Chlorine Cl Z17 \u2192P17 E17 N=35-17=18 \u2192\u00b3\u2075Cl\u2081\u2087 Configuration 2,8,7 Valency1\u0964 Answer Key Mass number35 - Chlorine\u0964<\/b><br><br>\n\n<b>Q13. Neutrons 12 \u0935\u093e\u0932\u093e - \u092c\u0924\u093e\u0913\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u092f\u0926\u093f Carbon A=12+12=24? Actually Carbon Z6 N6 A12 \u0939\u094b\u0924\u093e - N12 \u0924\u094b A=Z+12 - \u0909\u0926\u093e\u0939\u0930\u0923 Mg Z12 N12 A24 \u2192\u00b2\u2074Mg\u2081\u2082\u0964 Answer Key Neutrons12\u0964<\/b><br><br>\n\n<b>Q14. (i)4 (ii)7 (iii)4 - \u0915\u094d\u092f\u093e?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Beryllium Z4 - K2 L2 Valency2, Nitrogen Z7 - K2 L5 Valency3, Beryllium \u092b\u093f\u0930\u0964 Answer Key (i)4 (ii)7 (iii)4\u0964<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"e8-3\" style=\"display:none;\"><div style=\"background:#2e7d32;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe2 \u092d\u093e\u0917 3\/5 - Q15-Q18<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q15. Electronic configuration \u0926\u093f\u090f \u0939\u0948\u0902 2,8,2 ; 2,8,6 ; 2,8,8 - \u092a\u0939\u091a\u093e\u0928\u094b\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: 2,8,2 \u2192Magnesium Mg Z12 Valency2 Metal, 2,8,6 \u2192Sulfur S Z16 Valency2 Non-metal, 2,8,8 \u2192Argon Ar Z18 Valency0 Noble gas \u0938\u094d\u0925\u093f\u0930\u0964 Answer Key \u092f\u0939\u0940\u0964<\/b><br><br>\n\n<b>Q16. Sodium 12 - \u0915\u094d\u092f\u093e?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Sodium Z11 \u0928\u0939\u0940\u0902 12 Magnesium - Sodium 2,8,1 Valency1 - \u0936\u093e\u092f\u0926 Protons 12 \u2192Mg 2,8,2\u0964 Answer Key Sodium 12 - Actually Na Z11 E11 2,8,1\u0964<\/b><br><br>\n\n<b>Q17. Average atomic mass \u0928\u093f\u0915\u093e\u0932\u094b Bromine \u0915\u093e \u0926\u094b isotope \u2077\u2079Br \u0914\u0930 \u2078\u00b9Br \u0932\u0917\u092d\u0917 \u092c\u0930\u093e\u092c\u0930 - Average?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (79+81)\/2=80 \u2192Exact 79.9 \u219280.006 u\u0964 Answer Key 80.006 u\u0964<\/b><br><br>\n\n<b>Q18. Isotopes \u0914\u0930 Isobars \u092e\u0947\u0902 \u0905\u0902\u0924\u0930 \u0909\u0926\u093e\u0939\u0930\u0923 \u0938\u0939\u093f\u0924\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Isotopes - Z \u0938\u092e\u093e\u0928 A \u092d\u093f\u0928\u094d\u0928 - H \u00b9H\u2081 \u00b2H\u2081 \u00b3H\u2081, C \u00b9\u00b2C\u2086 \u00b9\u2074C\u2086, Cl \u00b3\u2075Cl\u2081\u2087 \u00b3\u2077Cl\u2081\u2087 - Chemical same physical mass different\u0964 Isobars - A \u0938\u092e\u093e\u0928 Z \u092d\u093f\u0928\u094d\u0928 - Ar \u2074\u2070Ar\u2081\u2088 Ca \u2074\u2070Ca\u2082\u2080, C \u00b9\u2074C\u2086 N \u00b9\u2074N\u2087 - Chemical different\u0964<\/b><br><br>\n\n<b>Revise, Reflect, Refine - \u092a\u0947\u091c 155-157:<\/b><br>\n\n<b>Q1. \u0938\u0939\u0940 \u0915\u0925\u0928 \u0915\u094c\u0928? (i) Thomson model \u092e\u0947\u0902 electron \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0917\u094b\u0932\u0947 \u092e\u0947\u0902 (ii) Rutherford model \u092e\u0947\u0902 \u0928\u093e\u092d\u093f\u0915 \u0918\u0928\u093e \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 (iii) Bohr model \u092e\u0947\u0902 electrons \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 \u092e\u0947\u0902 (iv) \u0938\u092d\u0940\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (ii)(iii) \u0938\u0939\u0940 - Thomson \u092e\u0947\u0902 electron \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924 \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0917\u094b\u0932\u0947 \u092e\u0947\u0902 \u0907\u0938\u0932\u093f\u090f (i) \u092d\u0940 \u0938\u0939\u0940? Actually (ii)(iii) correct - Answer Key (ii)(iii) correct\u0964<\/b><br><br>\n\n<b>Q2. \u0938\u0939\u0940 \u0915\u094c\u0928? (i) Atomic number protons \u0938\u0902\u0916\u094d\u092f\u093e (ii) Mass number protons+neutrons (iii) ...<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (iii) correct - \u0938\u092d\u0940 \u0938\u0924\u094d\u092f Atomic number Z=Protons, Mass A=p+n\u0964 Answer Key (iii) correct\u0964<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"e8-4\" style=\"display:none;\"><div style=\"background:#ef6c00;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe0 \u092d\u093e\u0917 4\/5 - Q3-Q9 Revise<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q3. (i) Isotopes (ii) Isobars - \u092a\u0930\u093f\u092d\u093e\u0937\u093e \u0932\u093f\u0916\u094b\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (i) Isotopes same Z different A - H 1 2 3, Cl 35 37 (ii) Isobars different Z same A - Ar40 Ca40\u0964 Answer Key (i) Isotopes (ii) Isobars\u0964<\/b><br><br>\n\n<b>Q4. \u0915\u094d\u092f\u093e \u0939\u094b \u0905\u0917\u0930 atoms \u0915\u093f\u0938\u0940 \u092d\u0940 \u0905\u0928\u0941\u092a\u093e\u0924 \u092e\u0947\u0902 \u092e\u093f\u0932 \u0938\u0915\u0924\u0947 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u0905\u0928\u0941\u092a\u093e\u0924 \u0928\u0939\u0940\u0902?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0924\u092c \u092a\u0926\u093e\u0930\u094d\u0925\u094b\u0902 \u0915\u0947 \u0917\u0941\u0923 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u0928\u0939\u0940\u0902 \u0939\u094b\u0924\u0947 \u092a\u093e\u0928\u0940 \u0915\u092d\u0940 H:O 1:8 \u0915\u092d\u0940 2:8 \u092c\u0928\u0924\u093e \u0905\u0932\u0917 \u0917\u0941\u0923 \u0939\u094b\u0924\u093e \u0930\u0938\u093e\u092f\u0928 \u0935\u093f\u091c\u094d\u091e\u093e\u0928 \u0905\u0938\u094d\u0924-\u0935\u094d\u092f\u0938\u094d\u0924\u0964<\/b><br><br>\n\n<b>Q5. \u0915\u094d\u0930\u092e - \u092a\u0939\u0932\u0947 \u092a\u0942\u091b\u093e \u0917\u092f\u093e - \u0935\u0939\u0940\u0964<\/b><br><br>\n\n<b>Q6. Electrons \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u0915\u094d\u092f\u094b\u0902 \u0928\u0939\u0940\u0902 \u0917\u093f\u0930\u0924\u0947?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Bohr \u0905\u0928\u0941\u0938\u093e\u0930 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0928\u0939\u0940\u0902 \u0916\u094b\u0924\u0947 electrostatic attraction centripetal force \u0938\u0902\u0924\u0941\u0932\u093f\u0924\u0964<\/b><br><br>\n\n<b>Q7. Assertion: Thomson plum pudding model \u092e\u0947\u0902 ... Reason ...<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (ii) Both true but R not correct explanation - Answer Key (ii)\u0964<\/b><br><br>\n\n<b>Q8. Magnesium 12 12 12 - \u092a\u0939\u0932\u0947 \u092c\u0924\u093e\u092f\u093e - Answer Key Protons12 Neutrons12 Electrons12 2,8,2\u0964<\/b><br><br>\n\n<b>Q9. Lithium Nitrogen Aluminium Fluorine - \u092a\u0939\u0932\u0947 \u092c\u0924\u093e\u092f\u093e - Answer Key Li 3 1 1 3 3, N 7 5 3 7 7, Al 13 3 3 13 13, F 9 7 1 9 9\u0964<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"e8-5\" style=\"display:none;\"><div style=\"background:#004d40;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\u2705 \u092d\u093e\u0917 5\/5 - Q10-Q15 + \u0938\u093e\u0930<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q10. Element X \u092e\u0947\u0902 6 electrons \u092c\u093e\u0939\u0930\u0940 \u0915\u094b\u0936 \u092e\u0947\u0902 diatomic molecule \u092c\u0928\u093e\u0924\u093e \u0915\u094d\u092f\u094b\u0902? \u0915\u093f\u0938 \u092a\u094d\u0930\u0915\u093e\u0930 \u092c\u0902\u0927? \u0938\u0902\u0930\u091a\u0928\u093e?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: X=Oxygen 2,6 \u092c\u093e\u0939\u0930\u0940 6 2 \u091a\u093e\u0939\u093f\u090f \u0926\u094b O \u0926\u094b-\u0926\u094b \u0938\u093e\u091d\u093e O\u2082 O=O \u0926\u094d\u0935\u093f\u092c\u0902\u0927 covalent - \u0938\u094d\u0925\u093f\u0930 \u0939\u094b\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f\u0964<\/b><br><br>\n\n<b>Q11. Neutrons 39 \u0935\u093e\u0932\u093e \u0924\u0924\u094d\u0935 - \u092c\u0924\u093e\u0913\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Potassium K Z19 A=19+39=58? Actually K-39 \u092e\u0947\u0902 N20 \u0939\u094b\u0924\u093e - K-41 \u092e\u0947\u0902 N22 - \u092f\u0926\u093f N39 \u0924\u094b A=Z+39 - \u0909\u0926\u093e\u0939\u0930\u0923 Yttrium Z39? \u0932\u0947\u0915\u093f\u0928 Answer Key Neutrons39 - Bromine Br Z35 N45 A80 \u092e\u0947\u0902 N45 \u0939\u094b\u0924\u093e - 39 \u0935\u093e\u0932\u093e? - \u0938\u093e\u092e\u093e\u0928\u094d\u092f\u0964<\/b><br><br>\n\n<b>Q12. Table \u092a\u0942\u0930\u093e \u0915\u0930\u094b Atomic number Mass number Neutrons Protons Electrons Name:<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Atomic5 Mass11 Neutrons6 Protons5 Electrons5 Boron B 2,3<br>\nAtomic7 Mass14 Neutrons7 Protons7 Electrons7 Nitrogen N 2,5<br>\nAtomic12 Mass24 Neutrons12 Protons12 Electrons12 Magnesium Mg 2,8,2<br>\nAtomic15 Mass31 Neutrons16 Protons15 Electrons15 Phosphorus P 2,8,5<br>\nAtomic1 Mass1 Neutrons0 Protons1 Electrons1 Hydrogen H 1 - Answer Key \u092a\u0947\u091c 272 \u092f\u0939\u0940\u0964<\/b><br><br>\n\n<b>Q13. Chlorine \u0915\u0947 \u092c\u093e\u0930\u0947 \u092e\u0947\u0902 - Electrons17 Protons17 Atomic17 Chlorine Configuration2,8,7 Valence7 Mass37 Isotopes - \u092c\u0924\u093e\u0913\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Cl Z17 P17 E17 Configuration2,8,7 Valence7 Valency1 Mass35\/37 Average35.5 Isotopes \u00b3\u2075Cl \u00b3\u2077Cl\u0964 Answer Key Electrons17 Protons17 Atomic17 Chlorine 2,8,7 Valence7 Mass37 Isotopes\u0964<\/b><br><br>\n\n<b>Q14. Species 11 protons 12 neutrons 10 electrons \u0924\u094b (i) atomic number mass number (ii) neutral cation anion (iii) configuration (iv) name - Chapter 9 \u092e\u0947\u0902 \u092d\u0940 \u0906\u092f\u093e\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Z11 A23 (11+12) Cation 11p10e 1+ Configuration2,8 Sodium cation Na\u207a\u0964<\/b><br><br>\n\n<b>Q15. Applications - Isotopes \u0915\u0947 \u0909\u092a\u092f\u094b\u0917 - U235 nuclear fuel, Co60 cancer, I131 thyroid, C14 dating - \u092a\u0939\u0932\u0947 \u092c\u0924\u093e\u092f\u093e\u0964<\/b><br><br>\n\n<div style=\"background:#fff9c4;border:3px solid #fbc02d;padding:10px;border-radius:10px;text-align:center;font-weight:bold;\">\n\u2705 Chapter 8 \u0938\u093e\u0930\u0940 \u092a\u094d\u0930\u0936\u094d\u0928\u093e\u0935\u0932\u0940 \u0936\u0941\u0926\u094d\u0927 \u0916\u0924\u094d\u092e - \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 \u091b\u0942\u091f\u093e - Answer Key \u092a\u0947\u091c 272 \u0938\u0947 \u092e\u093f\u0932\u093e\u092f\u093e<br><br>\n\u091f\u094d\u0930\u093f\u0915: Model \u0915\u094d\u0930\u092e Dalton indivisible \u2192Thomson plum pudding \u2192Rutherford nucleus Gold foil \u2192Bohr KLMN fixed energy \u2192Quantum cloud<br>\nSubatomic e\u207b Thomson negative KLMN, p\u207a Goldstein positive nucleus Z, n\u2070 Chadwick 0 nucleus stability<br>\nK L M N 2n\u00b2 K2 L8 M18 \u092c\u093e\u0939\u0930\u0940 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902 Na 2,8,1 Mg 2,8,2 Al 2,8,3 Cl 2,8,7 Ar 2,8,8 octet stable Valency \u092c\u093e\u0939\u0930\u09401-4=\u092c\u093e\u0939\u0930\u0940 5-7=8-\u092c\u093e\u0939\u0930\u0940 8=0<br>\nZ=p=e \u0909\u0926\u093e\u0938\u0940\u0928 A=p+n n=A-Z Mg24 12 p12 e12 n12 2,8,2 Fe26 26 30 56 Cl35 17 17 18 B5 11 6 5 5 Boron N7 14 7 7 7 H1 1 0 1 1<br>\nAverage (35\u00d775+37\u00d725)\/100=35.5 Br 80.006, Isotopes Z \u0938\u092e\u093e\u0928 A \u092d\u093f\u0928\u094d\u0928 H1 2 3 C12 14 Cl35 37 chemical same uses U235 Co60 I131 C14, Isobars A \u0938\u092e\u093e\u0928 Z \u092d\u093f\u0928\u094d\u0928 Ar40 Ca40 C14 N14 chemical different<br>\n\u092a\u0915\u094d\u0915\u093e 3 \u092a\u094d\u0930\u0936\u094d\u0928 \u0905\u0917\u094d\u0928\u093f\u0935\u0940\u0930 \u092e\u0947\u0902 \u0907\u0938\u0940 \u0938\u0947\n<\/div>\n\n<\/div><\/div>\n<\/div>\n\n<div style=\"background:#4a148c;padding:12px;display:flex;justify-content:space-between;align-items:center;\">\n<button type=\"button\" id=\"e8p\" style=\"background:#ffcc00;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">&larr; \u092a\u0940\u091b\u0947<\/button>\n<span id=\"e8i\" style=\"background:#fff;color:#4a148c;padding:8px 20px;border-radius:20px;font-weight:bold;\">1 \/ 5<\/span>\n<button type=\"button\" id=\"e8n\" style=\"background:#00e676;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">\u0906\u0917\u0947 &rarr;<\/button>\n<\/div>\n<\/div>\n\n<script>\n(function(){\nvar c=1,t=5;\nfunction s(n){\nfor(var i=1;i<=t;i++){\nvar el=document.getElementById('e8-'+i);\nif(el)el.style.display=(i===n?'block':'none');\n}\ndocument.getElementById('e8i').textContent=n+' \/ '+t;\nc=n;\n}\ndocument.getElementById('e8n').onclick=function(){var n=c+1;if(n>t)n=1;s(n);};\ndocument.getElementById('e8p').onclick=function(){var n=c-1;if(n<1)n=t;s(n);};\n})();\n<\/script><\/div><\/div><\/div><\/div><div id=\"pg-845-3\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-845-3-0\"  class=\"panel-grid-cell\" ><div id=\"panel-845-3-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"3\" ><div class=\"textwidget custom-html-widget\"><div id=\"AG8\" style=\"max-width:860px;margin:12px auto;border:4px solid #4a148c;border-radius:14px;background:#ede7f6;font-family:'Noto Sans Devanagari',Arial,sans-serif;overflow:hidden;\">\n<div style=\"background:#4a148c;padding:10px;text-align:center;\"><span style=\"background:#fff;color:#4a148c;padding:7px 20px;border-radius:20px;font-weight:bold;font-size:14px;\">\u0905\u0917\u094d\u0928\u093f\u0935\u0940\u0930 \u0915\u0947 \u0932\u093f\u090f - Chapter 8 - 25 MCQ - PDF \u0938\u0947 \u0936\u0941\u0926\u094d\u0927<\/span><\/div>\n\n<div style=\"padding:10px 12px;\">\n<div id=\"ag8-1\" style=\"display:block;\"><div style=\"background:#b71c1c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd34 \u092d\u093e\u0917 1\/5 - Q1-Q5<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q1. \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0949\u0921\u0932 \u0935\u093f\u0915\u093e\u0938 \u0915\u094d\u0930\u092e \u0915\u094d\u092f\u093e \u0939\u0948? [Fig8.16 \u092a\u0947\u091c157 PDF]<\/b><br>\nA) Dalton indivisible 1808 \u2192 Thomson plum pudding positive negative 1904 \u2192 Rutherford nucleus dense mostly empty 1911 \u2192 Bohr energy levels KLMN fixed 1913 \u2192 Modern Quantum still discovered B) \u0909\u0932\u094d\u091f\u093e C) \u0915\u0947\u0935\u0932 Bohr D) \u0915\u0947\u0935\u0932 Dalton<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) - \u091f\u094d\u0930\u093f\u0915: D-T-R-B-M<\/b><br><br>\n\n<b>Q2. \u0909\u092a-\u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0923 \u0916\u094b\u091c \u0915\u093f\u0938\u0928\u0947 \u0915\u0940? [\u092a\u0947\u091c 154-156]<\/b><br>\nA) Electron J.J.Thomson Cathode ray -1.6\u00d710\u207b\u00b9\u2079 C 9.1\u00d710\u207b\u00b3\u00b9 kg KLMN \u092e\u0947\u0902, Proton Goldstein canal ray \u0928\u093e\u092e Rutherford +1.6\u00d710\u207b\u00b9\u2079 1.67\u00d710\u207b\u00b2\u2077 \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 Z, Neutron James Chadwick 1932 0 1.67\u00d710\u207b\u00b2\u2077 \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u0938\u094d\u0925\u093f\u0930\u0924\u093e B) \u0915\u0947\u0935\u0932 Thomson C) \u0915\u0947\u0935\u0932 Rutherford D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q3. Thomson \u092e\u0949\u0921\u0932 \u0915\u094d\u092f\u093e \u0939\u0948? \u0915\u092e\u0940?<\/b><br>\nA) Plum pudding - \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924 \u0917\u094b\u0932\u0947 \u092e\u0947\u0902 \u090b\u0923\u093e\u0935\u0947\u0936\u093f\u0924 electrons \u0927\u0902\u0938\u0947 \u091c\u0948\u0938\u0947 \u0916\u0940\u0930 \u092e\u0947\u0902 \u0915\u093f\u0936\u092e\u093f\u0936 \u0924\u0930\u092c\u0942\u091c \u092e\u0947\u0902 \u092c\u0940\u091c \u0909\u0926\u093e\u0938\u0940\u0928 - \u0915\u092e\u0940 Gold foil \u092a\u094d\u0930\u092f\u094b\u0917 \u0938\u092e\u091d\u093e \u0928\u0939\u0940\u0902 \u092a\u093e\u092f\u093e \u0928\u093e\u092d\u093f\u0915 \u0928\u0939\u0940\u0902 \u092c\u0924\u093e\u092f\u093e B) \u0915\u0947\u0935\u0932 \u0928\u093e\u092d\u093f\u0915 C) \u0915\u0947\u0935\u0932 orbit D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q4. Rutherford Gold Foil \u092a\u094d\u0930\u092f\u094b\u0917 \u0928\u093f\u0937\u094d\u0915\u0930\u094d\u0937? [\u092a\u0947\u091c 155]<\/b><br>\nA) Alpha \u0915\u0923 He\u00b2\u207a \u0938\u094b\u0928\u0947 \u092a\u0928\u094d\u0928\u0940 \u092a\u0930 - \u0905\u0927\u093f\u0915\u093e\u0902\u0936 \u0938\u0940\u0927\u0947 \u0928\u093f\u0915\u0932\u0947 \u2192 \u092a\u0930\u092e\u093e\u0923\u0941 \u0905\u0927\u093f\u0915\u093e\u0902\u0936 \u0916\u093e\u0932\u0940, \u0915\u0941\u091b \u0925\u094b\u0921\u093c\u093e \u0935\u093f\u091a\u0932\u093f\u0924 \u2192 \u0928\u093e\u092d\u093f\u0915 \u0918\u0928\u093e \u0927\u0928\u093e\u0935\u0947\u0936\u093f\u0924, \u092c\u0939\u0941\u0924 \u0915\u092e 1\/20000 \u0935\u093e\u092a\u0938 \u2192 \u0928\u093e\u092d\u093f\u0915 \u091b\u094b\u091f\u093e \u0924\u094d\u0930\u093f\u091c\u094d\u092f\u093e 1\/100000 \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u093e, electrons \u0928\u093e\u092d\u093f\u0915 \u091a\u093e\u0930\u094b\u0902 \u0913\u0930 \u092a\u0930\u093f\u0915\u094d\u0930\u092e\u093e - \u0915\u092e\u0940 electron \u090a\u0930\u094d\u091c\u093e \u0916\u094b\u0915\u0930 \u0928\u093e\u092d\u093f\u0915 \u092e\u0947\u0902 \u0917\u093f\u0930\u0928\u093e \u091a\u093e\u0939\u093f\u090f \u0938\u094d\u0925\u093f\u0930\u0924\u093e \u0928\u0939\u0940\u0902 B) \u0915\u0947\u0935\u0932 \u0916\u093e\u0932\u0940 C) \u0915\u0947\u0935\u0932 \u0918\u0928\u093e D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q5. Bohr \u092e\u0949\u0921\u0932 \u0915\u094d\u092f\u093e? Rutherford \u0938\u0947 \u092c\u0947\u0939\u0924\u0930 \u0915\u094d\u092f\u094b\u0902? [\u092a\u0947\u091c 156]<\/b><br>\nA) Electrons \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0924\u0930 Orbits Shells K L M N n=1 2 3 4 \u092e\u0947\u0902 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e K \u0938\u092c\u0938\u0947 \u0915\u092e \u0928\u093e\u092d\u093f\u0915 \u0928\u093f\u0915\u091f - orbit \u092c\u0926\u0932 \u0924\u092d\u0940 \u090a\u0930\u094d\u091c\u093e \u0905\u0935\u0936\u094b\u0937\u0923 \u0909\u0924\u094d\u0938\u0930\u094d\u091c\u0928 - Rutherford \u0915\u092e\u0940 \u0926\u0942\u0930 electron \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u090a\u0930\u094d\u091c\u093e \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0928\u0939\u0940\u0902 \u0916\u094b\u0924\u093e \u0907\u0938\u0932\u093f\u090f \u0938\u094d\u0925\u093f\u0930 - Electrostatic attraction centripetal force B) \u0915\u0947\u0935\u0932 K C) \u0915\u0947\u0935\u0932 L D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"ag8-2\" style=\"display:none;\"><div style=\"background:#1565c0;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd35 \u092d\u093e\u0917 2\/5 - Q6-Q10<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q6. \u0915\u094b\u0936 Shell K L M N \u0905\u0927\u093f\u0915\u0924\u092e electrons \u0938\u0942\u0924\u094d\u0930? [\u092a\u0947\u091c 157]<\/b><br>\nA) 2n\u00b2 - K n1 \u21922\u00d71=2, L n2 \u21922\u00d74=8, M n3 \u21922\u00d79=18 \u0932\u0947\u0915\u093f\u0928 \u092c\u093e\u0939\u0930\u0940 \u092e\u0947\u0902 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902 octet \u0928\u093f\u092f\u092e, N n4 \u21922\u00d716=32 \u092c\u093e\u0939\u0930\u0940 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902 - \u092a\u0939\u0932\u0947 K \u092b\u093f\u0930 L \u092b\u093f\u0930 M B) \u0915\u0947\u0935\u0932 2 C) \u0915\u0947\u0935\u0932 8 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q7. \u0907\u0932\u0947\u0915\u094d\u091f\u094d\u0930\u0949\u0928\u093f\u0915 \u0935\u093f\u0928\u094d\u092f\u093e\u0938 \u0932\u093f\u0916\u094b - Na 11 Mg 12 Al 13 Cl 17 Ar 18? [\u092a\u0947\u091c 158 Table8.4]<\/b><br>\nA) Na 11 \u21922,8,1 K2 L8 M1, Mg12 \u21922,8,2, Al13 \u21922,8,3, Cl17 \u21922,8,7, Ar18 \u21922,8,8 \u0938\u094d\u0925\u093f\u0930 octet - H1 \u21921 K1, He2 \u2192K2 duplet \u0938\u094d\u0925\u093f\u0930, Li3 \u21922,1, Be4 \u21922,2, B5 \u21922,3, C6 \u21922,4, N7 \u21922,5, O8 \u21922,6, F9 \u21922,7, Ne10 \u21922,8 \u0938\u094d\u0925\u093f\u0930 B) \u0915\u0947\u0935\u0932 Na C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 Ar<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q8. \u0938\u094d\u0925\u093f\u0930\u0924\u093e Stability \u0914\u0930 Valency \u0915\u094d\u092f\u093e? [\u092a\u0947\u091c 158-159]<\/b><br>\nA) \u092c\u093e\u0939\u0930\u0940 octet 8 He K \u092c\u093e\u0939\u0930\u0940 2 duplet \u0924\u094b \u0938\u094d\u0925\u093f\u0930 unreactive Noble gas Ne 2,8 Ar 2,8,8 - 8 \u0938\u0947 \u0915\u092e \u0905\u0938\u094d\u0925\u093f\u0930 \u0916\u094b\u0915\u0930 \u092a\u093e\u0915\u0930 \u0938\u093e\u091d\u093e octet \u0915\u094b\u0936\u093f\u0936 Chemical Bond Chapter9 - Valency combining capacity \u091c\u093f\u0924\u0928\u0947 \u0916\u094b\u090f \u092a\u093e\u090f \u0938\u093e\u091d\u093e - \u092c\u093e\u0939\u0930\u0940 1-4=\u092c\u093e\u0939\u0930\u0940 \u0926\u0947\u0928\u093e, 5-7=8-\u092c\u093e\u0939\u0930\u0940 \u0932\u0947\u0928\u093e, 4=4 \u0938\u093e\u091d\u093e, 8=0 B) \u0915\u0947\u0935\u0932 octet C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 Valency<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q9. Valency \u0928\u093f\u0915\u093e\u0932\u094b - Li N Al F? [Fig8.17 Answer Key \u092a\u0947\u091c272]<\/b><br>\nA) Li 2,1 \u092c\u093e\u0939\u0930\u09401 \u21921 \u0926\u0947\u0928\u093e Valency1 Total3 Protons3 Atomic3, N 2,5 \u092c\u093e\u0939\u0930\u09405 \u21928-5=3 \u0932\u0947\u0928\u093e Valency3 Total7 Protons7 Atomic7, Al 2,8,3 \u092c\u093e\u0939\u0930\u09403 \u21923 \u0926\u0947\u0928\u093e Valency3 Total13 Protons13 Atomic13, F 2,7 \u092c\u093e\u0939\u0930\u09407 \u21921 \u0932\u0947\u0928\u093e Valency1 Total9 Protons9 Atomic9 B) \u0915\u0947\u0935\u0932 Li C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 F<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) - Mg 2,8,2 \u21922, Na 2,8,1 \u21921, Cl 2,8,7 \u21921, Ar 2,8,8 \u21920, C 2,4 \u21924, O 2,6 \u21922, S 2,8,6 \u21922<\/b><br><br>\n\n<b>Q10. Atomic number Z \u0914\u0930 Mass number A \u0915\u094d\u092f\u093e? \u0938\u0942\u0924\u094d\u0930? [\u092a\u0947\u091c 159]<\/b><br>\nA) Z = Protons \u0938\u0902\u0916\u094d\u092f\u093e = Electrons \u0909\u0926\u093e\u0938\u0940\u0928 \u092e\u0947\u0902 - \u0924\u0924\u094d\u0935 \u092a\u0939\u091a\u093e\u0928 - A = Protons+Neutrons = Z+n = \u0915\u0941\u0932 Nucleons - Neutrons = A-Z - Notation \u1d2cX_Z \u091c\u0948\u0938\u0947 \u00b2\u2074Mg\u2081\u2082 \u00b3\u2075Cl\u2081\u2087 \u00b9\u00b2C\u2086 B) \u0915\u0947\u0935\u0932 Z C) \u0915\u0947\u0935\u0932 A D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"ag8-3\" style=\"display:none;\"><div style=\"background:#2e7d32;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe2 \u092d\u093e\u0917 3\/5 - Q11-Q15<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q11. Mg Mass24 Atomic12 \u0924\u094b Protons Neutrons Electrons Configuration? [Q8 Answer Key]<\/b><br>\nA) Protons=Z=12 Electrons12 Neutrons=A-Z=24-12=12 Configuration2,8,2 K2 L8 M2 - Fe Electrons26 Protons26 Neutrons30 \u2192Z26 A56 2,8,14,2 B) \u0915\u0947\u0935\u0932 Protons C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 Neutrons<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) Answer Key Protons12 Neutrons12 Electrons12 2,8,2<\/b><br><br>\n\n<b>Q12. Table \u092a\u0942\u0930\u093e \u0915\u0930\u094b - B5 11, N7 14, Mg12 24, P15 31, H1 1? [\u092a\u0947\u091c272 Answer Key]<\/b><br>\nA) B Atomic5 Mass11 Neutrons6 Protons5 Electrons5 Boron 2,3, N7 14 Neutrons7 Protons7 Electrons7 Nitrogen 2,5, Mg12 24 Neutrons12 Protons12 Electrons12 Magnesium 2,8,2, P15 31 Neutrons16 Protons15 Electrons15 Phosphorus 2,8,5, H1 1 Neutrons0 Protons1 Electrons1 Hydrogen 1 B) \u0915\u0947\u0935\u0932 B C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 Mg<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q13. Average atomic mass \u0915\u0948\u0938\u0947 \u0928\u093f\u0915\u093e\u0932\u0924\u0947? Cl 35.5 \u0915\u0948\u0938\u0947? [\u092a\u0947\u091c 160]<\/b><br>\nA) Relative abundance \u0906\u0927\u093e\u0930 - \u0938\u0942\u0924\u094d\u0930 Average = (Mass1\u00d7%1+Mass2\u00d7%2)\/100 - Cl \u00b3\u2075Cl 75% \u00b3\u2077Cl 25% \u2192(35\u00d775+37\u00d725)\/100=3550\/100=35.5 u, B \u00b9\u2070B20% \u00b9\u00b9B80% \u219210.8 u 10.81, Br \u2077\u2079Br \u2078\u00b9Br \u0932\u0917\u092d\u0917 \u092c\u0930\u093e\u092c\u0930 80.006 u B) \u0915\u0947\u0935\u0932 35 C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 37<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) Answer Key 80.006 u<\/b><br><br>\n\n<b>Q14. Isotopes \u0915\u094d\u092f\u093e? \u0909\u0926\u093e\u0939\u0930\u0923 \u0917\u0941\u0923 \u0909\u092a\u092f\u094b\u0917? [\u092a\u0947\u091c 161]<\/b><br>\nA) Same Z different A - p \u0938\u092e\u093e\u0928 n \u092d\u093f\u0928\u094d\u0928 - H \u00b9H\u2081 p1n0 Protium \u00b2H\u2081 p1n1 Deuterium \u092d\u093e\u0930\u0940 \u091c\u0932 \u00b3H\u2081 p1n2 Tritium \u0930\u0947\u0921\u093f\u092f\u094b\u0927\u0930\u094d\u092e\u0940, C \u00b9\u00b2C 6p6n 98.9% \u00b9\u2074C 6p8n dating, Cl \u00b3\u2075Cl 17p18n 75% \u00b3\u2077Cl 17p20n 25%, O \u00b9\u2076O \u00b9\u2077O \u00b9\u2078O, U \u00b2\u00b3\u2075U 92p143n \u00b2\u00b3\u2078U 92p146n - Chemical same electron \u0938\u092e\u093e\u0928 physical mass \u092d\u093f\u0928\u094d\u0928 - Uses U235 Nuclear fuel, Co60 Cancer treatment, I131 Thyroid, C14 Fossil dating, Na24 Blood clot B) \u0915\u0947\u0935\u0932 H C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 Cl<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q15. Isobars \u0915\u094d\u092f\u093e? \u0909\u0926\u093e\u0939\u0930\u0923? [\u092a\u0947\u091c 162]<\/b><br>\nA) Different Z same A - A \u0938\u092e\u093e\u0928 Z \u092d\u093f\u0928\u094d\u0928 p \u092d\u093f\u0928\u094d\u0928 n \u092d\u093f\u0928\u094d\u0928 \u0932\u0947\u0915\u093f\u0928 p+n \u0938\u092e\u093e\u0928 - Ar \u2074\u2070Ar\u2081\u2088 18p22n \u0914\u0930 Ca \u2074\u2070Ca\u2082\u2080 20p20n A40 Z18 Z20 \u092d\u093f\u0928\u094d\u0928, C \u00b9\u2074C\u2086 6p8n N \u00b9\u2074N\u2087 7p7n A14 Z6 Z7 \u092d\u093f\u0928\u094d\u0928 - Chemical different electron \u092d\u093f\u0928\u094d\u0928 B) \u0915\u0947\u0935\u0932 Isotopes C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 Ar<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"ag8-4\" style=\"display:none;\"><div style=\"background:#ef6c00;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe0 \u092d\u093e\u0917 4\/5 - Q16-Q20<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q16. Chlorine \u092c\u093e\u0930\u0947 - Electrons17 Protons17 Atomic17 Configuration Valence Mass Isotopes? [Answer Key \u092a\u0947\u091c272]<\/b><br>\nA) Cl Z17 P17 E17 Configuration2,8,7 Valence7 Valency1 Mass35\/37 Average35.5 Isotopes \u00b3\u2075Cl \u00b3\u2077Cl B) \u0915\u0947\u0935\u0932 17 C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 35<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) Answer Key Electrons17 Protons17 Atomic17 Chlorine 2,8,7 Valence7 Mass37 Isotopes<\/b><br><br>\n\n<b>Q17. Species 11 protons 12 neutrons 10 electrons \u0924\u094b Z A Cation Anion Configuration Name? [Q12 Chapter9 \u092d\u0940]<\/b><br>\nA) Z=11 A=23 11+12 Protons11 Electrons10 \u21921+ Cation Configuration2,8 Na\u207a Sodium cation B) Anion C) Neutral D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) Answer Key Z11 A23 Cation 2,8 Na\u207a<\/b><br><br>\n\n<b>Q18. Electronic configuration 2,8,2 2,8,6 2,8,8 \u092a\u0939\u091a\u093e\u0928\u094b? [Q15 Answer Key]<\/b><br>\nA) 2,8,2 \u2192Mg Z12 Valency2 Metal, 2,8,6 \u2192S Z16 Valency2 Non-metal, 2,8,8 \u2192Ar Z18 Valency0 Noble gas stable B) \u0915\u0947\u0935\u0932 Mg C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 Ar<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q19. \u0938\u0939\u0940 \u0915\u0925\u0928 \u0915\u094c\u0928? (i) Thomson electrons embedded positive sphere (ii) Rutherford mostly empty dense nucleus (iii) Bohr fixed energy levels?<\/b><br>\nA) (ii)(iii) correct - Thomson \u092d\u0940 \u0938\u0939\u0940 positive sphere \u092e\u0947\u0902 negative \u0932\u0947\u0915\u093f\u0928 Answer Key (ii)(iii) correct - Bohr fixed, Rutherford dense B) \u0915\u0947\u0935\u0932 (i) C) \u0915\u0947\u0935\u0932 (ii) D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) Answer Key (ii)(iii) correct<\/b><br><br>\n\n<b>Q20. Atomic number Mass number \u092c\u093e\u0930\u0947 \u0938\u0939\u0940? (i) Z=Protons (ii) A=p+n (iii) ...?<\/b><br>\nA) (iii) correct - Z=Protons=Electrons neutral, A=Total nucleons p+n, n=A-Z, Notation \u1d2cX_Z B) \u0915\u0947\u0935\u0932 (i) C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 (ii)<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) Answer Key (iii) correct<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"ag8-5\" style=\"display:none;\"><div style=\"background:#004d40;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\u2705 \u092d\u093e\u0917 5\/5 - Q21-Q25 + \u091f\u094d\u0930\u093f\u0915<\/div><div style=\"background:#fff;border:1.5px solid #4a148c;border-radius:10px;padding:12px;font-size:14px;line-height:2;height:580px;overflow-y:auto;\">\n\n<b>Q21. Isotopes Isobars \u092e\u0947\u0902 \u0905\u0902\u0924\u0930 \u0915\u094d\u092f\u093e?<\/b><br>\nA) Isotopes Z \u0938\u092e\u093e\u0928 A \u092d\u093f\u0928\u094d\u0928 p \u0938\u092e\u093e\u0928 n \u092d\u093f\u0928\u094d\u0928 Chemical same H1 2 3 Cl35 37, Isobars A \u0938\u092e\u093e\u0928 Z \u092d\u093f\u0928\u094d\u0928 p \u092d\u093f\u0928\u094d\u0928 Chemical different Ar40 Ca40 C14 N14 B) \u0938\u092e\u093e\u0928 C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 Isotopes<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) Answer Key (i)Isotopes (ii)Isobars<\/b><br><br>\n\n<b>Q22. Average atomic mass Bromine 79 81 \u0932\u0917\u092d\u0917 \u092c\u0930\u093e\u092c\u0930 Average?<\/b><br>\nA) 80.006 u - (79+81)\/2\u224880 Exact 79.9 B) 79 C) 81 D) 35.5<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) Answer Key 80.006 u<\/b><br><br>\n\n<b>Q23. Valency 0 \u0915\u093f\u0938\u0915\u0940? Noble gas?<\/b><br>\nA) Ne 2,8 Ar 2,8,8 He K2 duplet stable octet Valency0 Largely unreactive B) Na C) Cl D) Mg<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q24. \u092c\u093e\u0939\u0930\u0940 1-4 Valency = \u092c\u093e\u0939\u0930\u0940, 5-7 =8-\u092c\u093e\u0939\u0930\u0940 \u0909\u0926\u093e\u0939\u0930\u0923 C 2,4?<\/b><br>\nA) C 2,4 \u092c\u093e\u0939\u0930\u09404 \u2192Valency4 \u0938\u093e\u091d\u093e, N 2,5 \u21923, O 2,6 \u21922, F 2,7 \u21921, Li 2,1 \u21921, Be 2,2 \u21922, B 2,3 \u21923, Na 2,8,1 \u21921, Mg 2,8,2 \u21922, Al 2,8,3 \u21923, Si 2,8,4 \u21924, P 2,8,5 \u21923, S 2,8,6 \u21922, Cl 2,8,7 \u21921 B) \u0915\u0947\u0935\u0932 C C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 N<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q25. K L M N \u092e\u0947\u0902 \u0905\u0927\u093f\u0915\u0924\u092e electrons \u0914\u0930 \u092c\u093e\u0939\u0930\u0940 \u0928\u093f\u092f\u092e?<\/b><br>\nA) K2 L8 M18 N32 \u0938\u0942\u0924\u094d\u0930 2n\u00b2 \u0932\u0947\u0915\u093f\u0928 \u092c\u093e\u0939\u0930\u0940 \u092e\u0947\u0902 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902 octet \u0928\u093f\u092f\u092e - \u092a\u0939\u0932\u0947 K \u092b\u093f\u0930 L \u092b\u093f\u0930 M \u092d\u0930\u0924\u093e B) \u0915\u0947\u0935\u0932 K2 C) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 D) \u0915\u0947\u0935\u0932 L8<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<div style=\"background:#fff9c4;border:3px solid #fbc02d;padding:10px;border-radius:10px;text-align:center;font-weight:bold;\">\n\u2705 \u0905\u0917\u094d\u0928\u093f\u0935\u0940\u0930 \u091f\u094d\u0930\u093f\u0915 Chapter 8 - PDF \u0938\u0947 \u0936\u0941\u0926\u094d\u0927<br><br>\nModel \u0915\u094d\u0930\u092e D-T-R-B-M Dalton indivisible \u2192Thomson plum pudding \u0916\u0940\u0930 \u0915\u093f\u0936\u092e\u093f\u0936 \u2192Rutherford Gold foil \u0916\u093e\u0932\u0940 \u0918\u0928\u093e \u0928\u093e\u092d\u093f\u0915 1\/100000 \u2192Bohr KLMN fixed energy \u0938\u094d\u0925\u093f\u0930 \u2192Quantum cloud still discovered<br>\nSubatomic e\u207b Thomson - +? Negative -1.6\u00d710\u207b\u00b9\u2079 9.1\u00d710\u207b\u00b3\u00b9 KLMN, p\u207a Goldstein +1.6\u00d710\u207b\u00b9\u2079 1.67\u00d710\u207b\u00b2\u2077 \u0928\u093e\u092d\u093f\u0915 Z, n\u2070 Chadwick 0 1.67\u00d710\u207b\u00b2\u2077 \u0928\u093e\u092d\u093f\u0915 stability<br>\nShell K L M N 2n\u00b2 K2 L8 M18 N32 \u092c\u093e\u0939\u0930\u0940 8 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0928\u0939\u0940\u0902 octet - Na 2,8,1 Mg 2,8,2 Al 2,8,3 Cl 2,8,7 Ar 2,8,8 stable octet He K2 duplet<br>\nValency \u092c\u093e\u0939\u0930\u09401-4=\u092c\u093e\u0939\u0930\u0940 5-7=8-\u092c\u093e\u0939\u0930\u0940 8=0 Li1 Be2 B3 C4 N3 O2 F1 Ne0 Na1 Mg2 Al3 Si4 P3 S2 Cl1 Ar0 - Li N Al F Total Valence Valency Protons Atomic<br>\nZ=p=e neutral A=p+n n=A-Z Mg24 12 p12 e12 n12 2,8,2 Fe26 26 30 56 Cl35 17 17 18 B5 11 6 5 5 Boron N7 14 7 7 7 P15 31 16 15 15 H1 1 0 1 1<br>\nAverage (35\u00d775+37\u00d725)\/100=35.5 Br80.006, Isotopes Z \u0938\u092e\u093e\u0928 A \u092d\u093f\u0928\u094d\u0928 p \u0938\u092e\u093e\u0928 n \u092d\u093f\u0928\u094d\u0928 H1 2 3 C12 14 Cl35 37 chemical same uses U235 fuel Co60 cancer I131 thyroid C14 dating Na24 blood, Isobars A \u0938\u092e\u093e\u0928 Z \u092d\u093f\u0928\u094d\u0928 Ar40 Ca40 C14 N14 chemical different<br>\n\u092a\u0915\u094d\u0915\u093e 5 \u092a\u094d\u0930\u0936\u094d\u0928 \u0905\u0917\u094d\u0928\u093f\u0935\u0940\u0930 \u092e\u0947\u0902 \u0907\u0938\u0940 \u0938\u0947\n<\/div>\n\n<\/div><\/div>\n<\/div>\n\n<div style=\"background:#4a148c;padding:12px;display:flex;justify-content:space-between;align-items:center;\">\n<button type=\"button\" id=\"ag8p\" style=\"background:#ffcc00;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">&larr; \u092a\u0940\u091b\u0947<\/button>\n<span id=\"ag8i\" style=\"background:#fff;color:#4a148c;padding:8px 20px;border-radius:20px;font-weight:bold;\">1 \/ 5<\/span>\n<button type=\"button\" id=\"ag8n\" style=\"background:#00e676;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">\u0906\u0917\u0947 &rarr;<\/button>\n<\/div>\n<\/div>\n\n<script>\n(function(){\nvar c=1,t=5;\nfunction s(n){\nfor(var i=1;i<=t;i++){\nvar el=document.getElementById('ag8-'+i);\nif(el)el.style.display=(i===n?'block':'none');\n}\ndocument.getElementById('ag8i').textContent=n+' \/ '+t;\nc=n;\n}\ndocument.getElementById('ag8n').onclick=function(){var n=c+1;if(n>t)n=1;s(n);};\ndocument.getElementById('ag8p').onclick=function(){var n=c-1;if(n<1)n=t;s(n);};\n})();\n<\/script><\/div><\/div><\/div><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>Chapter 8 &#8211; Journey Inside the Atom &#8211; \u0938\u093e\u092e\u093e\u0928\u094d\u092f \u092a\u0930\u093f\u091a\u092f &#8211; \u0936\u0941\u0926\u094d\u0927 \ud83d\udd34 \u092d\u093e\u0917 1\/5 &#8211; \u092a\u0930\u092e\u093e\u0923\u0941 \u092e\u0949\u0921\u0932 \u0915\u093e \u0935\u093f\u0915\u093e\u0938 Fig 8.16 \u092a\u0947\u091c 157 &#8211; Journey of development of atomic models \u0915\u094d\u0930\u092e: &#8211; Dalton Atomic model &#8211; Atom as indivisible particle &#8211; 1808 &#8211; Thomson Atomic model &#8211; Positive and negative charge &#8211; plum pudding [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29],"tags":[],"class_list":["post-845","post","type-post","status-publish","format-standard","hentry","category-science"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Science &#187; *Chapter 8* | Journey Inside the Atom | \u092a\u0930\u092e\u093e\u0923\u0941 \u0915\u0947 \u0905\u0902\u0926\u0930 \u0915\u0940 \u092f\u093e\u0924\u094d\u0930\u093e &#187; Class-9th - Agniveer Foundation Hub | Pargai Defence &amp; Academic.<\/title>\n<meta name=\"description\" content=\"Class 9 Online Classes in Bageshwar with NCERT Textbook based study material, chapter-wise learning, MCQs, assignments and Agniveer Foundation. 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