With increase in nuclear charge the nuclear attraction for outer electrons increases, hence ionization potential increases.

With increase in nuclear charge the nuclear attraction for outer electrons increases, hence ionization potential increases.
X | Y |
---|---|
1: Element with atomic number 19 | A: Group 18 [0 group] |
2: Element with electronic configuration 2 | B: Group 16 [VI A] |
3: Element with a valency of -2 | C: Group 1 [IA] |
4: Element ‘P’ which loses 3 electrons to form a cation | D: Group 17 [VII A] |
5: Element ‘Q’ in period-3 which has the highest electron affinity | E: Group 13 [III A] |