Chapter 19, Problem 19.3QE

Interpretation Introduction

Interpretation:

The ratio of the density of tantalum to that of niobium is $\text{1}\text{.94}$, which is nearly identical to the $1.95$ ratio of their atomic weights. How this similarity is a result of the lanthanide contraction has to be explained.

Concept Introduction:

Lanthanide contraction:

The poor shielding of $\text{4f}$ orbital on nuclear charge results the increasing the attraction of $\text{6s}$ electrons towards the nucleus, it causes the atomic size reduction.