Oregon Esthetician State Board

What is the subtraction of oxygen or the addition of hydrogen called?

1. Oxidation

2. Reduction

3. Synthesis

4. Electrolysis

The correct answer is: Reduction

The process of subtraction of oxygen or the addition of hydrogen is termed reduction. Reduction refers specifically to a chemical reaction in which a substance gains electrons or hydrogen, effectively reducing its oxidation state. In the context of redox reactions, which involve the transfer of electrons, reduction is one half of the process that also includes oxidation, where a substance loses electrons or gains oxygen. This foundational concept is critical in chemistry, particularly in the study of organic compounds and reactions. Understanding reduction helps estheticians appreciate how certain chemical reactions can affect skin care ingredients and their efficacy, particularly in treatments aimed at improving skin quality and function. The other terms presented—oxidation, synthesis, and electrolysis—represent different chemical processes that do not align with the definition of reduction. Oxidation involves the opposite process, where a substance loses electrons. Synthesis is about combining elements or compounds to form a more complex substance. Electrolysis refers to using an electric current to drive a chemical reaction, which is not specifically about the gain of hydrogen or loss of oxygen.