Lowest Ionisation Energy Elements ⚡ JEE Shortcut
❓ Question Group 14 elements A and B have first ionisation enthalpy values: A → 708 kJ mol⁻¹ B → 715 kJ mol⁻¹ These are the lowest values in the group . Find the nature of their ions: A 2 + and B 4 + A^{2+} \quad \text{and} \quad B^{4+} 🖼 Question Image ✍️ Short Concept Ionisation energy generally decreases down the group . Lowest values in Group 14 correspond to the heaviest elements . So these numbers help identify the elements. 🔷 Step 1 — Identify the Elements 💯 Group 14 elements: C → Si → Ge → Sn → Pb Ionisation energies: Sn ≈ 708 kJ/mol Pb ≈ 715 kJ/mol So: A = S n A = Sn B = P b B = Pb 🔷 Step 2 — Apply Inert Pair Effect In heavier p-block elements: ns² electrons become reluctant to participate in bonding. This is called: Inert Pair Effect \textbf{Inert Pair Effect} Because of this: Lower oxidation states become more stable . 🔷 Step 3 — Nature of A 2 + A^{2+} (Sn²⁺) Tin: Stable oxidation states: + 2 and + 4 +2 \quad...