What happens to the rate of a reaction as the reaction progresses?

C

Explanation:

The rate of a reaction decreases as time progresses. ... If the amount of reactant particles is decreasing as the reaction progresses, then the chance of successful collisions must also decrease, and ultimately when all the reactant particles have reacted, the reaction must stop and the rate become zero.

c

Explanation:

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.