In chemical terms, what is the result of reduction?

In chemical terms, reduction is defined as the gain of electrons by an atom, molecule, or ion. This process often occurs in conjunction with oxidation, where one substance loses electrons while another gains them.

When reduction takes place at the cathode during electrochemical reactions, the gain of electrons leads to a decrease in the oxidation state of the substance being reduced. For example, in a galvanic cell, the cathode is where reduction occurs, resulting in a buildup of electrons and a change in charge state of the substances involved.

The other options provide scenarios that do not accurately represent the concept of reduction. Loss of electrons occurs during oxidation, which does not align with the principles of reduction. An increase in temperature is unrelated to electron transfer mechanisms and does not directly indicate a reduction or oxidation process. Similarly, while depletion of hydrogen ions could occur in certain specific chemical reactions, it does not define the general process of reduction.