Would repolarization without the presence of proteins occur? Explain your response

No.

Repolarization would not be possible since K+ being hydrophilic would not be able to move across plasma membrane.

Explanation:

Repolarization happen when the current outside plasma membrane exceed the inside current. It is a stage of action potential in which the cell experiences a reduction of voltage due to potassium ion (K+) efflux along it's electrochemical gradients. Potassium ions leaving the membrane potential become more negative. When the potassium ion move out,it make the membrane more negative. This is the process of repolarization.

idk lol use google m8

its temperature is increasing. this causes molecular vibrations to increase.