Question

What is the trend for Electron Affinity?

Answer 1

Electron affinity

• The amount of energy released when an electron is added to a neutral atom to form an anion is called electron affinity.

Trend for electron affinity

• Generally, on going down the group, electron affinity decreases because of the increase in the size of the atoms.
• Generally, ongoing left to right, the value of electron affinity increases because of increased nuclear attraction.

Example of the electron affinity of halogen

• The correct order of electron affinity is $\mathrm{Cl}>\mathrm{F}>\mathrm{Br}$.
• The electron affinity of fluorine is less than chlorine because the size of fluorine is too small whereas chlorine has a larger size to accommodate electrons.