The chemical equation for the reaction of lithium metal and bromine gas is:

2 Li (s) + Br₂ (g) → 2 LiBr (s)

Here's a breakdown:

* Li (s) represents lithium metal in its solid state.

* Br₂ (g) represents bromine gas in its gaseous state.

* LiBr (s) represents lithium bromide, the product of the reaction, in its solid state.

This is a combination reaction where lithium and bromine combine to form lithium bromide. The reaction is highly exothermic, meaning it releases a significant amount of heat.