The electronic configuration of Eu₃⁺ ion is:

The electronic configuration of the Eu³⁺ ion, which is the trivalent form of europium, can be determined by first looking at the electron configuration of neutral europium (Eu). Europium has an atomic number of 63, and its neutral electron configuration is:

Neutral Europium Configuration

Eu: [Xe] 6s² 4f⁷

Understanding Ionization

When europium loses three electrons to form the Eu³⁺ ion, the electrons are removed first from the 6s orbital and then from the 4f orbital. Thus, the configuration for Eu³⁺ becomes:

Eu³⁺ Ion Configuration

Eu³⁺: [Xe] 4f⁷

Summary

• Neutral Europium: [Xe] 6s² 4f⁷
• Europium Ion (Eu³⁺): [Xe] 4f⁷

This configuration indicates that the Eu³⁺ ion has seven electrons in the 4f subshell, which is characteristic of its chemical behavior and properties.