General Science

  • adjective referring to a chemical that reacts easily with other substances


  • Tending to easily form part of a chemical reaction. For example, fluorine is the one of the most reactive of all chemical elements, and forms compounds with almost every other element, usually quite vigorously.
  • Tending to respond to an action or stimulus. Also, tending to respond to an action or stimulus more than others within the same category or group.
  • Pertaining to, causing, utilizing, or arising from reactance.


  • adjective taking place as a reaction to something else


  • adjective dealing with a problem once it has started to occur