Bromine plus hydrogen reacts to form hydrogen bromide (HBr). This reaction is an example of a halogenation reaction, where a halogen (bromine in this case) is added to a molecule.

Here's the chemical equation for the reaction:

Br₂ + H₂ → 2HBr

Important Note: This reaction requires specific conditions to occur, such as heat or a catalyst.

Hydrogen bromide (HBr) is a colorless, corrosive gas with a pungent odor. It is a strong acid and is commonly used in the production of other chemicals and in the synthesis of organic compounds.