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.
A chemical element or element is a chemical substance consisting of atoms having the same number of protons in their atomic nuclei (i.e. the same atomic number, Z).he properties of the chemical elements are often summarized using the periodic table, which powerfully and elegantly organizes the elements by increasing atomic number into rows (periods) in which the columns (groups) share recurring (periodic) physical and chemical properties.