Based on the equation below, which of the following statements best describes what should be observed as the reaction takes place? (you can pick multiple) Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g)

(A) Bubbles forming from chlorine gas production

(B) Bubbles forming from hydrogen gas production

(C) Chlorine forming a solid precipitate

(D) Solid zinc dissolving

a is the correct answer

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.