Question

"Of the alkali metals, only Na forms nitrides."
Answer whether the above statement is true or false.
If true enter 1, else enter 0.

Answer 1

Of the alkali metals, only $Li$ forms nitrides. This is because of lattice energies that only lithium forms a stable oxide and nitride.

When Lithium reacts with nitrogen gas at room temperature $\left(N_2\right)$, it forms Lithium Nitride $\left(L{i}_{3}N\right)$ which is stable because the lattice energy released from the formation of $L{i}_{3}N$ is high enough to make the overall reaction exothermic. For other alkali metals (Na, K, Rb, Cs), the lattice energy for the $M_{3}N$ crystal is progressively lesser, and therefore, these compounds are highly unstable or do not form at all.