What happens in a chemical reaction? А
Substances change in appearance but not in chemical composition.
B
Substances change from solid to liquid or gas.
с
Substances interact to form one or more new substances.
D
New atoms are created or destroyed.

In a chemical reaction, the number of moles of the reactants a. should never be equal to the number of moles of the products. b. may or may not be equal to the number of moles of the products. c. depends on the amount of product that is formed. d. should always be equal to the number of moles of the products.