Na\(_2\)X ⇌ 2Na\(^+\) + X\(^{2-}\) The bond between Na and X is likely to be

The equation Na\(_2\)X \(\rightleftharpoons\) 2Na\(^+\) + X\(^{2-}\) shows the compound Na\(_2\)X dissociating into its constituent ions: sodium ions (Na\(^+\)) and an anion X\(^{2-}\).

This dissociation into oppositely charged ions is the hallmark of an ionic bond. In ionic bonding, one or more electrons are transferred from a metal atom (here, sodium) to a non-metal atom (here, X). Sodium loses one electron to form Na\(^+\), while X gains two electrons to form X\(^{2-}\). Two sodium atoms are needed to supply the two electrons that X requires.

The other bond types do not fit:

• A covalent bond involves the sharing of electron pairs between atoms, not transfer and complete dissociation into ions.
• A dative (coordinate) bond is a special covalent bond where both shared electrons come from one atom.
• A metallic bond involves a "sea" of delocalised electrons shared among metal atoms in a lattice - it does not produce discrete anions like X\(^{2-}\).