Chemistry - PERIODIC TABLE Question with Solution | TestHub

(A) Solubility: Group-1 carbonates generally become more soluble down the group: Na₂CO₃ < K₂CO₃ < Rb₂CO₃ < Cs₂CO₃.

(B) Lattice energy: Higher ionic charge and smaller ions give greater lattice energy; hence NaF < MgO < ScN < TiC.

(C) Covalent character: For PbX₂, anion size/polarizability increases F⁻ → I⁻, so covalent character increases: PbF₂ < PbCl₂ < PbBr₂ < PbI₂.

(D) Stability: Trihalide ions become more stable down the group due to increasing polarizability: Cl₃⁻ < Br₃⁻ < I₃⁻.

Therefore, all A, B, C and D are correct.