Question

Ionisation potential increases across a period, from left to right. Give reason

Answer 1

Definition of ionisation potential

It is defined as the amount of energy required to remove an electron from an isolated gaseous atom resulting in the formation of cation

• Across a period, the atomic size decreases and nuclear charge increases.
• The force of attraction between the nucleus and valence electron increases.
• So greater energy is required to remove an electron from its valence shell.
• Hence ionisation potential increases from left to right in a period