Which among the following alkali metals readily reacts with Nitrogen and form stable nitride?
Li
Na
K
Both 1 and 2
Lithium is the only alkali metal which readily reacts with nitrogen at room temperature due to its small size and high polarising power. The lithium nitride is stable.
Other alkali metals when reacted with nitrogen would not release enough lattice energy and therefore, the reaction would be endothermic. Even if the reaction occurs, the nitrides are unstable.