Question

what us the lonisation enthalpy.how does it very in a group and along the pariod​

Answer 1

The size increases as we move from top to bottom in a group. As, the electrons get added up in the new shell, the electron in the outermost orbital gets far away from the nucleus. And hence, the electron will be easier to remove. Thus, the ionization enthalpy decreases from top to bottom in a group.