The second ionisation enthalpy of the elements of group `1` are higher than those of elements of group `2`. Explain.

Explain why the ionisation ethalpies of the elements of group - 15 are much higher than those of group - 14.

The first ionisation enthalpies (Delta_iH_1) of group-13 elements are lower than those of elements of group 2-Explain.

The second ionisation enthalpies of both Cr and Cu are higher than those of the next element. Explain.

The second ionisation enthalpies of both Cr and Cu are higher than those of the next element. Explain.

Explain ionisation enthalpy of group 14 elements .

The second ionisation enthalpies of both chromium and copper are higher than those of the next element. Why?

Give reason : First ionisation enthalpies of 5d elements are higher than those of 3d and 4d elements.