The reaction 2K(s) + Br2(l) → 2KBr(s) represents a combination reaction where potassium (K), a solid metal, reacts with bromine (Br2), a liquid halogen, to form potassium bromide (KBr), a solid ionic compound. This reaction is exothermic, releasing energy as heat and light due to the formation of strong ionic bonds in KBr. The reactants are in their standard states, and the reaction typically occurs rapidly and can be quite vigorous, especially with potassium, which is highly reactive.