Reactions eventually stop. What is generally the reason for this?
A. The catalyst has been used up.
B. The particles have run out of energy.
C. One or more of the reactants has been used up.

Reactions eventually stop. Generally the reason for this :

C. One or more of the reactants has been used up.

Explanation:

A reaction is an action taken in response to something. If you're telling your parents that you want to move out, you'll see by their reaction that they're sad about it. A reaction is often a physical in nature. A chemical reaction describes the way a chemical behaves when combined with another substance.Reactants are substances initially present in a chemical reaction that are consumed during the reaction to make products. Some chemical reactions go to completion, resulting in all of the reactants becoming products. These reactions are said to be irreversible. All chemical reactions involve both reactants and products. Reactants are substances that start a chemical reaction, and products are substances that are produced in the reactionFor example, burning methane in oxygen is irreversible.In a chemical reaction, reactants that are not used up when the reaction is finished are called excess reagents.

The answer is d.potassium