Question

Arrange F₂, Cl₂, Br₂, and I₂ in the increasing order of electron affinities.

Hint:

Electron affinity decreases as you move down Group 17 (halogens) due to the increase in atomic size.

Answer 1

Step 1: Electron Affinity Trends.
Electron affinity refers to the energy released when an electron is added to a neutral atom in the gas phase. For halogens, electron affinity generally increases from left to right across the period but decreases down the group.
Step 2: Electron Affinity of Halogens.
- F₂ has the highest electron affinity, followed by Cl₂, then Br₂, and finally I₂. This trend is because as we move down the group, the atomic size increases, and the attraction between the nucleus and the added electron decreases, leading to a lower electron affinity.
Step 3: Increasing Order.
\[ \text{I}_2<\text{Br}_2<\text{Cl}_2<\text{F}_2 \]