Question

Which of the following is the strongest oxidizing agent?
A. ${F_2}$
B. $B{r_2}$
C. $C{l_2}$
D. ${I_2}$

Answer 1

Hint: The substances which have the ability to oxidise other substances are called oxidising agents. In the process, they themselves are reduced.

Complete step by step answer:
Oxidising agent is a substance that is capable of oxidising other substances. In the process, they accept electrons from the other substance and are themselves reduced. In one sense, an oxidizing agent is a chemical species that undergoes a chemical reaction in which it gains one or more electrons. Thus, it is one component of a redox reaction. In another sense, an oxidizing agent is a chemical species that transfers electronegative atoms, usually oxygen, to a substrate.
As we move down a group, the electronegativity of the elements decreases. Thus, the power to attract electrons decreases and the electropositivity (the power to give away electrons) increases. Also, the effective nuclear charge decreases down a group. So, the ability to attract a shared pair of electrons decreases down a group. Hence, the oxidising ability decreases down the group. Thus, ${F_2}$ is the best oxidising agent in the halogen family.

Hence, the correct answer is (A).

Note: Remember that when we move left to right in a period, the electronegativity of the elements increases and their electropositivity decreases. Thus, they can attract the shared electrons more efficiently. Hence, the oxidising ability increases as we move along a period from left to right.