Answer
Fluorine and Chlorine are expected to be good oxidizing agents based on periodic trends.
Work Step by Step
Oxidizing agent means those elements or substances that are reduced (gain electrons) in a reaction and helps other substance to oxidize.
a. Potassium:- Potassium is Group IA metal on the periodic table. So, it has the tendency to lose electron and become oxidized (Any metal has the tendency to lose electron and become oxidized). So, it can be a good reducing agent but not an oxidizing agent.
b. Fluorine:- If we look at the periodic table, we can see Fluorine on Grp. VII on the table i.e. Halogen series. Halogens are non-metal in nature and they have tendencies to gain electron and become reduced. So, they can become a good oxidizing agent. That's why Fluorine is a good oxidizing agent.
c. Iron: Iron is a metal and it has tendency to lose electron and become oxidized. So, it is a good reducing agent but not an oxidizing agent.
d. Chlorine: Chlorine is a non-metal and it has tendency to gain electron and become reduced. So, it is a good oxidizing agent.
