How many lone pairs are on the p in pci3?

In phosphorus trichloride (PCl₃), the phosphorus atom is the central atom surrounded by three chlorine atoms. Phosphorus has five valence electrons, and each chlorine atom forms a single bond with phosphorus, using three of its electrons. This leaves two electrons as a lone pair on the phosphorus atom. Therefore, there is one lone pair on the phosphorus in PCl₃.