Increasing the concentration and increasing the temperature both increase reaction rates based on which physical phenomenon? 1. increasing the frequency of molecular collisions 2. decreasing the activation energy 3.increasing the behavior of inhibitors 4.decreasing the speed of phase change

You can deal with this question using the collision theory, which states that the chemical reactions occur when particles collide with enough energy to reach the Activation Energy.

The velocity of the particles is related with the temperature. At higher temperatures,  higher velocities and higher frequency of collisions.

Also, at higher concentration (more particles is a same volume) the number of collisions will increase.

Then, hIgher concentration and higher temperature will increase the frequency of the molecular collisions..

Then, the answer is the proposal #1: "increasing the frequency of molecular collisions"
 

What are you trying to ask?