What is the electron configuration for phosphide ions?

The electron configuration for phosphide ions, which are represented as P³⁻, involves adding three electrons to the neutral phosphorus atom's configuration.

Neutral Phosphorus Atom

A neutral phosphorus atom has an atomic number of 15, meaning it has 15 electrons. Its electron configuration is:

• 1s² 2s² 2p⁶ 3s² 3p³

Phosphide Ion Formation

When phosphorus gains three electrons to form the phosphide ion (P³⁻), the configuration changes to:

• 1s² 2s² 2p⁶ 3s² 3p⁶

Final Configuration

This configuration can also be simplified by noting that it resembles the electron configuration of argon, a noble gas:

• 1s² 2s² 2p⁶ (which is the same as argon)

In summary, the electron configuration for the phosphide ion is the same as that of argon, indicating a stable, filled outer shell.