JAMB Chemistry 2024 Paper

Concept:The compound $\mathrm{Na}_2\mathrm{X}$ contains sodium, a metal, and X, a nonmetal, so the bonding is ionic.Explanation:In the dissociation $\mathrm{Na}_2\mathrm{X} \rightleftharpoons 2\mathrm{Na}^{+} + \mathrm{X}^{2-}$, each sodium atom loses one electron, while X gains two electrons.This electron transfer creates oppositely charged ions: $\mathrm{Na}^{+}$ and $\mathrm{X}^{2-}$.The electrostatic attraction between these oppositely charged ions forms an ionic bond.Covalent and dative bonds involve electron sharing, not transfer.Metallic bonding occurs between metal atoms only, not between a metal and a nonmetal.Answer:C. ionic