JAMB - Chemistry (2025 - No. 91)

The reaction given, \(\text{Na}_{2}\text{X}\rightleftharpoons 2\text{Na}^{+}+\text{X}^{2-}\), indicates that the compound \(\text{Na}_{2}\text{X}\) dissociates into positive sodium ions (\(\text{Na}^{+}\)) and a negative ion (\(\text{X}^{2-}\)). The formation of ions and their electrostatic attraction is characteristic of an ionic bond.

Sodium (Na) is a metal and typically loses electrons to form positive ions (cations) to achieve a stable electron configuration. Element X forms a negative ion (\(\text{X}^{2-}\)), meaning it is likely a non-metal that gains electrons.