Nomenclature Definition List




Chemical nomenclature is concerned with naming chemical compounds and writing their formulas. Gathered below are definitions of many terms used in nomenclature. 

For definitions concerning bonds, see the definition list in the bonding section 



 
oxidation state an alternate term that can be used when referring to the charge on an atom (but not a polyatomic ion.) There is a technical definition to this work, but it occurs later in the course. See the Redox section for more information.
metalloid an element which has the capacity to act as either a metal or a nonmetal, depending on the chemical circumstances
nonmetal  an element that tends to gain electrons, becoming negatively charged; see anion
metal an element that tends to lose electrons, becoming positively charged; see cation
ion an atom or group of atoms with either a positive or a negative charge 
cation positively charged ion.
anion negatively charged ion. The phrase "anions are negative ions" might help you to remember.
monoatomic ion a single atom ion (mono means one) Ex: Na+ or Cl¯
polyatomic ion a many atom ion (poly means many) which acts chemically as one unit. 
Example: NO3¯ (1 Nitrogen atom, 3 Oxygen atoms and an extra electron giving the ion a charge of 1¯. It does not have a 3¯ charge). 
ionic compound a compound containing at least one ionic bond (contains metal(s) & nonmetal(s)) 
covalent compound a compound containing only covalent bonds (covalent compounds are really molecules; contains only nonmetal atoms) 
binary ionic compound ionic compound with only 2 kinds of atoms
binary molecular compound covalent compound with only 2 kinds of atoms 
Copyright © 1996 by John L. Park 
 
ChemTeam at Diamond Bar High School, California, U.S.A.
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