What is the process of combustion of two or more elements to form a third known as?

The process described is known as fusion, which typically refers to the joining of two or more atomic nuclei to form a heavier nucleus, often releasing energy in the process. In chemical terms, however, combustion commonly involves a reaction with oxygen that results in the formation of new compounds, which may lead to confusion here.

In this context, it’s also important to differentiate it from other relevant processes. Decomposition involves breaking down a compound into simpler substances, evaporation concerns the transition of a substance from liquid to gas, and oxidation generally refers to a reaction in which a substance loses electrons, often involving the addition of oxygen.

The focus on combustion highlights a reaction where elements, particularly fuels reacting with oxidizers, lead to the production of new compounds, primarily involving oxidation rather than fusion. Thus, while the initial classification under "fusion" is understandable in the broader sense of forming new chemical entities, combustion is more accurately linked with oxidation processes.