Which of the following has the strongest bleaching property?

1. Fluorine
2. Chlorine
3. Iodine
4. Bromine

Chlorine is strongest bleaching property.

Chlorine is a very strong oxidizing agent, which is used commercially as a bleaching agent and as a disinfectant, It is strong enough to oxidize the dyes that give wood pulp its yellow or brown color, for example, thereby bleaching out this color, and strong enough to destroy bacteria and thereby acts as a germicide.