A general term for a chemical which accelerates a reaction without becoming chemically involved is called a

energizer

activator

accelerator

catalyst

Answer: Catalyst

Explanation:

The catalyst is a chemical which accelerates a reaction decreasing the activation energy, that is the energy that is necessary for a reaction occur. We can see in a standard graphic that the uncatalyzed reaction has a big curve while the catalyzed reaction has a minor curve. It shows the more facility that a catalyzed reaction has to occur.

D. Catalyst

Explanation:

A catalyst is a substance that speeds up a chemical reaction, but it is not consumed by the reaction. Hence a catalyst can be recovered chemically unchanged at the end of the reaction.

A catalyst lowers the activation energy and hence a large number of reactant particles collide and undergoes reaction. The particles have enough energy since the activation energy which is the minimum energy required for a reaction to occur becomes less.