The boiling point of group 15 follows the order.

The melting point rise from nitrogen to arsenic because of the continuous rise in the nuclear size. The low MP of nitrogen is because of its discrete diatomic particles. Though, that the nuclear size increases from arsenic to antimony, there is a decrease in their MP. Despite the fact that antimony has a layered structure, it has a low melting point than arsenic on account of the generally easy compressing of particles. Furthermore, the MP of bismuth is not as much as antimony because of the packing of atoms loosely by metallic holding.