Riot control agent. After September 11, 2001, the _____________ was established to provide a framework that provides a comprehensive national approach, applicable at all jurisdictional levels and across functional disciplines.
noun, plural: chemicals. (1) A substance made up of chemical elements or produced from a chemical process. (2) A drug, especially illicit or addictive drug. adjective. Of, relating to, or pertaining to, chemistry or a chemical substance.
chemistry. 1  the science that deals with the composition and properties of substances and various elementary forms of matter. 2  chemical properties, reactions, phenomena, etc.: the chemistry of carbon. 3  the interaction of one personality with another: The chemistry between him and his boss was all wrong.