In redox reactions, what occurs to the substance that loses electrons?

In redox reactions, the substance that loses electrons undergoes a process known as oxidation. When a substance loses electrons, it often corresponds to an increase in oxidation state. This is a fundamental principle of redox chemistry: oxidation and reduction always occur simultaneously, meaning that while one substance is losing electrons (being oxidized), another is gaining those electrons (being reduced).

Oxidation is often associated with the addition of oxygen or the removal of hydrogen from a substance, but the key defining characteristic is the loss of electrons. For instance, when zinc reacts with copper sulfate, zinc loses electrons and is oxidized to zinc ions, while the copper ions gain those electrons and are reduced to copper metal.

This relationship between oxidation and the loss of electrons is established in the concept of redox reactions, where one reactant is oxidized and another is reduced, thus maintaining the balance of charge and mass within the reaction.