A chemical reaction is a process that involves the rearrangement of the molecular or ionic structure of a substance, resulting in the formation of one or more new substances with different physical and chemical properties. Full definition
Even the simplest flames are complicated, a dance of chemical reactions in which molecules interact in hundreds of different ways. (discovermagazine.com)
In our bodies, oxygen is constantly involved in chemical reactions in which electrons are shifted around to generate energy. (brightfocus.org)
This is a result of chemical reaction between the two ingredients, and it's perfectly safe to eat. (thekitchn.com)