Question

Why does first ionization energy goes on decreasing down the group ?​

Answer 1

As we move down a group the ionic radii increases as a reasult the screening effect becomes greater than the effectinuclear charge.

As a reasult the energy required to remove the electron from the valence shell becomes less and less. So the

first ionization energy goes on decreasing down the group.

Answer 2

Answer:

When moving to the right of a period, the number of electrons increases and the strength of shielding increases. As a result, it is easier for valence shell electrons to ionize, and thus the ionization energy decreases down a group. ... This is due to electron shielding.