Definition: Radical refers to the act or process of breaking something into pieces, often through chemical means. Definition: Radical (chemistry) is a verb meaning to break down or transform into simpler substances. It's typically used to describe chemical reactions that involve breaking down materials like atoms into smaller particles, such as making hydrogen and oxygen from nitrogen and carbon, respectively, or creating carbon dioxide gas from methane in an industrial process. For example, when we break down coal into charcoal, we're saying that it has been transformed into simpler elements. When we add water to the surface of a volcano, the volcanic ash is being broken up into smaller particles, which then becomes rock and soil. This transformation is what gives us rocks like granite and igneous rock, as well as creating minerals such as obsidian (a type of rock) and quartz.