Provide an example of the reactivity and oxidizing power of Group 7 elements.

Group 7 elements have high reactivity and oxidizing power.

Group 7 elements, also known as halogens, have high reactivity due to their electronegativity. They have seven valence electrons and require only one more electron to complete their outermost shell, making them highly reactive. This reactivity decreases down the group due to the increasing atomic radius and shielding effect.

The oxidizing power of Group 7 elements also increases down the group. This is because as the atomic radius increases, the attraction between the nucleus and the outermost electrons decreases, making it easier for the halogen to gain an electron and form a negative ion. This ability to gain electrons makes Group 7 elements strong oxidizing agents.

An example of the oxidizing power of Group 7 elements is their reaction with metals. Halogens can react with metals to form metal halides, with the halogen gaining an electron and the metal losing electrons. For example, chlorine can react with sodium to form sodium chloride, a common table salt. This reaction is highly exothermic and releases a large amount of energy.

In summary, Group 7 elements have high reactivity and oxidizing power due to their electronegativity and ability to gain electrons. This makes them important in many chemical reactions, including the formation of salts and other compounds.