Chapter 23, Problem 23.32P

(a)

Interpretation Introduction

Interpretation:

The reason for the $E{u}^{2+}$ ion is a common oxidation state has to be explained.

Concept Introduction:

The fourteen $4f$ electrons shield the outer electrons poorly from the increase in nuclear charge due to fourteen additional protons, resulting in a shrinkage in atomic size called the lanthanide contraction.

(b)

Interpretation Introduction

Interpretation:

The reason for the $T{b}^{2+}$ ion is a common oxidation state has to be explained.

Concept Introduction:

The fourteen $4f$ electrons shield the outer electrons poorly from the increase in nuclear charge due to fourteen additional protons, resulting in a shrinkage in atomic size called the lanthanide contraction.