Classification of Elements Part 2

Concept:Periodic trends in ionization energy, electron affinity, metallic character, and basicity of oxides depend on atomic size and effective nuclear charge.Explanation:Option A – First Ionization EnergyIonization energy increases across a period and decreases down a group.The given order $\mathrm{F} > \mathrm{P} > \mathrm{S} > \mathrm{B}$ is correct.Fluorine is the most electronegative, phosphorus has a half-filled p-subshell giving it extra stability over sulfur, and boron has the lowest IE.Option B – Electron AffinityElectron affinity generally increases across a period but chlorine has higher EA than fluorine due to smaller repulsion in its larger 3p orbital.The order $\mathrm{Cl} > \mathrm{F} > \mathrm{S} > \mathrm{P}$ is correct.Chlorine has the highest EA, followed by fluorine, then sulfur, and finally phosphorus.Option C – Metallic CharacterMetallic character increases down a group and decreases across a period.The given order $\mathrm{K} > \mathrm{Al} > \mathrm{Mg} > \mathrm{B}$ is incorrect.Correct order: $\mathrm{K} > \mathrm{Mg} > \mathrm{Al} > \mathrm{B}$ (Mg is more metallic than Al).Option D – Basic Character of OxidesBasicity of oxides increases down a group and decreases across a period.The order $\mathrm{K}_2\mathrm{O} > \mathrm{Na}_2\mathrm{O} > \mathrm{MgO} > \mathrm{Al}_2\mathrm{O}_3$ is correct.Potassium oxide is most basic, sodium oxide next, magnesium oxide weakly basic, and aluminium oxide is amphoteric.Thus, options A, B, and D are correct.Answer:B. A, B and D only