Final answer:
Collision theory explains how reactant concentration, temperature, and catalysts influence the rate of a chemical reaction.
Step-by-step explanation:
Collision theory explains that the rate of a chemical reaction depends on reactant concentration and the occurrence of effective collisions. Increasing the concentration of reactants increases the frequency of collisions, leading to a faster reaction rate. Temperature also affects reaction rate by increasing the energy available for collisions. A higher temperature results in more collisions and a faster reaction rate. Catalysts, on the other hand, decrease the activation energy required for a successful collision, increasing the number of effective collisions and the reaction rate.