Which halogen shows the highest oxidizing ability?

The halogen with the highest oxidizing ability is fluorine. Oxidizing ability refers to the tendency of a substance to gain electrons during a chemical reaction. Fluorine is the most electronegative element on the periodic table, which means it has a strong attraction for electrons. This high electronegativity allows fluorine to effectively pull electrons towards itself, making it an excellent oxidizing agent.

As you move down the group of halogens from fluorine to iodine, the oxidizing ability decreases. This trend occurs because the atomic radius increases, leading to a greater distance between the nucleus and the outer electrons, which reduces the effective nuclear charge felt by the outermost electrons. Consequently, larger halogens like iodine are less able to attract and gain electrons compared to smaller halogens like fluorine.

Therefore, fluorine's superior ability to accept electrons and form negative ions solidifies its position as the strongest oxidizing agent among the halogens.