Question

First Ionization enthalpy of transition metal do not show much variation explain

Answer 1

Explanation:

increase in the nuclear charge with atomic ... Why does K have more first ionisation energy than Cr? ... It does not remain unchanged.

Answer 2

The ionization energy increases due to the increase in the nuclear charge with an atomic number at the beginning of the series. Gradually, the shielding effect of the added electrons also increases. This shielding effect tends to decrease the attraction due to the nuclear charge. These two opposing factors lead to a rather gradual increase in the ionization energies in any transition series.