What term describes the process of a substance uniting with oxygen?

The term that describes the process of a substance uniting with oxygen is oxidation. This chemical reaction involves the addition of oxygen to a substance, which often results in the release of energy in the form of heat and light. Oxidation is a fundamental process in various chemical reactions, particularly in combustion and respiration.

In many cases, oxidation specifically refers to the loss of electrons from a substance during the reaction, but the key aspect is its association with oxygen. When materials oxidize, they can undergo significant changes in their properties and energy states. For example, when iron oxidizes, it forms rust, indicating a clear change that occurs due to its interaction with oxygen.

Combustion, while related to the presence of oxygen, is a broader term that encompasses the rapid oxidation of a substance, typically involving the release of heat and light. Thus, while combustion is a type of oxidation process, not all oxidation is combustion.

Reduction, on the other hand, involves the gain of electrons or the removal of oxygen, making it the opposite process to oxidation. Evaporation pertains to the phase change of a substance from liquid to gas and does not involve any chemical reaction with oxygen.

Understanding these concepts clarifies why oxidation is the correct term for the