Why do chemical reactions tend to speed up when the concentration of the reactants is increased?

Question

Quizplus · Accepted Answer

Increasing the concentration of reactants increases the number of available particles in the reaction mixture. This means that there are more reactant molecules present to collide with one another, increasing the likelihood of successful collisions and therefore increasing the reaction rate. The other options may be factors that contribute to the frequency and energy of collisions, but they are not the main reason why the reaction rate increases with increased concentration.

Why Do Chemical Reactions Tend to Speed Up When the Concentration