How do halogens react with metals?

Halogens react with metals to form metal halides, which are typically ionic compounds.

Halogens, which are found in Group 7 of the Periodic Table, are highly reactive non-metals. They readily react with metals to form metal halides. This reaction is a type of redox reaction, where the metal is oxidised (loses electrons) and the halogen is reduced (gains electrons).

For instance, if you react a halogen like chlorine with a metal such as sodium, you will get a metal halide, in this case, sodium chloride. The reaction can be represented as: 2Na(s) + Cl2(g) → 2NaCl(s). Here, sodium is oxidised as it loses electrons to form Na+ ions, and chlorine is reduced as it gains these electrons to form Cl- ions. The resulting compound, sodium chloride, is an ionic compound because it's formed from a metal and a non-metal.

The reactivity of halogens decreases down the group. This means that a more reactive halogen can displace a less reactive halogen from its halide. For example, chlorine (a more reactive halogen) can displace iodine (a less reactive halogen) from potassium iodide, a reaction represented as: Cl2(g) + 2KI(aq) → 2KCl(aq) + I2(s).

In summary, halogens react with metals to form metal halides through redox reactions. The reactivity of halogens decreases down the group, allowing for displacement reactions to occur. Understanding these reactions is crucial for mastering the chemistry of halogens and their interactions with metals.