Similar term(s): oxidation state.
The numerical value of the charge on an ion (cation or anion), describing the number of bonds which can be formed by the ion. Valencies may be respresented in different ways, that is, descriptively (e.g. divalent), with numbers (e.g. 2-) or with roman numerals (e.g. II) and may or may not include description of the charge (- or +).
Examples of valancies are sodium (Na+) which is monovalent or univalent and the carbonate ion (CO32-) which is divalent. Chrome can occur in -(II) to +(VI) valencies, but is most common in the elemental (0), divalent (II), trivalent (III) and hexavalent (VI) forms.
Source: GreenFacts
The higher the valency, the greater the ability of a compound to combine with other elements, such as hydrogen.
Bromate - Bromide - Chlorate - Chlorite - Inorganic mercury compounds - Nitrate & Nitrite - Ozone