Aunit of a compound is formed when group of answer choices two or more atoms of different elements chemically combine. one atom gives off radiation two or more atoms collide. at least three atoms of the same element chemically combine.

The equation below shows a chemical reaction. a + b + heat —> c + d according to the law of conservation of energy, which statement is true? a. the reactants absorb heat because they have less energy than the products. b. the products release heat because they have more energy than the reactants. c. the reactants generate heat because they have more energy than the products. d. the products require heat to form because they have less energy than the reactants.