Question

Transition metals generally have high densities due to:

• A. Low atomic mass and larger atomic radii
• B. High atomic mass and smaller atomic radii
• C. Low atomic mass and smaller atomic radii
• D. High atomic mass and larger atomic radii

Answer 1

Answer: (B)

High atomic mass and smaller atomic radii

Answer 2

Density ($\rho$) is defined as mass ($m$) per unit volume ($V$), i.e., $\rho = \frac{m}{V}$.

Transition metals have high atomic mass due to increasing nuclear charge and number of nucleons. They have relatively smaller atomic radii due to poor shielding of increasing nuclear charge by (n-1)d electrons, leading to increased effective nuclear charge that pulls outer electrons closer.

This combination of high mass and small volume results in high density.