Easy Practice — Set 2

Quick Recap — Trends in Detail

• Electron gain enthalpy is most negative for Cl (F is less negative due to its small, compact size and electron-electron repulsion).
• Isoelectronic species: radius decreases as nuclear charge increases ($O^{2-}>F^->Na^+>Mg^{2+}$).
• Diagonal relationships: Li-Mg, Be-Al (similar charge/radius ratios).
• Anomalies in ionisation enthalpy: Be $>$ B and N $>$ O (extra stability of filled/half-filled subshells).