Bromine is an element that often gains an electron to become a negatively charged ion. Potassium is an element that often loses an electron to become a positively charged ion. Why are bromine and potassium likely to react with one another?

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.