You're asking about the charge of phosphorus (P) as an ion. Here's how to figure that out:

* Phosphorus's Position on the Periodic Table: Phosphorus is in Group 15 (also called Group 5A) of the periodic table. Elements in this group tend to gain three electrons to achieve a stable octet (8 electrons) in their outer shell.

* Charge: Gaining three electrons gives phosphorus a charge of -3.

Therefore, the charge of phosphorus as an ion is P³⁻.