Question

Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special
emphasis on the following points:
(i) electronic configurations,
(ii) oxidation states,
(iii) ionisation enthalpies, and (iv) atomic sizes.

Answer 1

Certain elements in the second transition series have higher first ionisation enthalpies than elements corresponding to the same vertical column in the first transition series.
There are also elements in the 2nd transition series whose first ionisation enthalpies are
lower than those of the elements corresponding to the same vertical column in the 1st transition series.
(iv) Atomic size generally decreases from left to right across a period. Now, among the
three transition series, atomic sizes of the elements in the second transition series are
greater than those of the elements corresponding to the same vertical column in the first transition series. However, the atomic sizes of the elements in the third transition series are virtually the same as those of the corresponding members in the second transition series. This is due to lanthanoid contraction.