Valence refers to the tendency or capacity of an atom, molecule, ion or radical to gain, lose or share electrons in a chemical reaction. It is used to describe the ability of an element to form bonds with other atoms and can be used to predict how elements will behave when they combine chemically. In general terms, valence refers to the quality or state of being valuable or worthy, but it also has specific meanings within different fields such as chemistry, psychology, linguistics, and philosophy.