Which of the following statements about equilibrium is true? 1) Equilibrium favors the products when the energy of the products is higher than the energy of the reactants.
2) Equilibrium favors the reactants when the energy of the product is lower than the energy of the reactants.
3) Equilibrium favors the products when they are less stable than the starting material of a reaction
4) Equilibrium favors the products when they are more stable than the starting material of a reaction.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.