How is bromine’s reactivity different from chlorine’s and iodine’s?

Bromine’s chemical reactivity is intermediate, falling between that of chlorine and iodine. This trend is primarily driven by the periodic decrease in electronegativity and oxidizing power as one moves down the halogen group.12

Key differences in reactivity include:

• Oxidizing Strength: While bromine is a strong oxidizing agent, it is less powerful than chlorine. This is largely due to the weaker hydration of the bromide ion compared to the chloride ion. Consequently, chlorine can displace bromine from its compounds, while bromine can displace iodine.123
• Bonding: Metal-bromine bonds are generally weaker than corresponding metal-chlorine bonds. Additionally, while bromine reacts with hydrocarbons, it does so less readily than chlorine.1
• Stability: Organic bromo compounds are typically more dense, less volatile, less combustible, and less stable than their chloro counterparts.1
• General Trends: As atomic number increases, the first ionization energy decreases, contributing to the reduced reactivity of bromine and iodine compared to the highly reactive chlorine and fluorine.24

In summary, bromine exhibits a predictable, intermediate reactivity consistent with its position in the periodic table between chlorine and iodine.15