Due to pπ - pπ bonding interactions, nitrogen for N 2 but phosphorus forms and does not form a…

We know that Nitrogen and phosphorous belongs to the same group but having different period and due to larger atomic size Phosphorous is unable to form pi bond due to stearic misalignment and so it forms tetra-atomic molecule in which each $\mathrm{P}$ atom is linked with $3$ other $\mathrm{P}$ atoms by $3$ sigma bonds. On the other hand, due to smaller atomic size $\mathrm{N}$ forms $1$ sigma and $2$ pi bonds i.e. triple bonds with other $\mathrm{N}$ atom and exists as diatomic molecules.