Question

The atomic radii of the metals of the third (5d) series of transition elements are virtually the same as those of the corresponding members of the second (4d) series.WHY?

Answer 1

electronegativity increases slowly along the series from left to right.and decreases slowly from 4th period to 5th.but the electronegativity of 5th and 6th preoid are almost same for transition metals.thus the atomic radii of the third series of transition elements are virtually the ame as those of the corresponding members of second series.

Answer 2

Explanation:

due to poor shielding effect of d and f electron