Chemistry - CHEMICAL BONDING Question with Solution | TestHub

(A) H₂ has a higher boiling point than He because the H₂ molecule has a larger surface area and stronger London dispersion forces than the He atom.

(B) According to Fajan’s Rules, covalent character increases with higher cation charge and smaller size ($A{l}^{3+}$ > $M{g}^{2+}$ > $N{a}^{+}$), making AlCl₃ the most covalent.

(C) Due to the inert pair effect, the stability of the +2 oxidation state increases down Group 14, which makes PbX₂ significantly more stable than CX₂.

(D) Thermal stability of carbonates increases down Group 2 as cationic size increases ($B{e}^{2+}$ to $B{a}^{2+}$), which leads to less polarization of the carbonate ion.

Since all these chemical principles are correctly applied, all four options (A, B, C, and D) are correct.