Question

Give a reason for each of the following.
(ii) Ionisation potential increases across a period, from left to right.

Answer 1

Ionization potential

1. It is the energy required to remove an electron from the valence shell of an atom in its isolated gaseous state.
2. Ionization potential increases across a period from left to right.
3. This is because across a period the atomic size decreases and also the nuclear charge increases.

Hence, due to a decrease in atomic size and increase in nuclear charge the ionization potential increase across a period.