But what is the valence of an atom?
Valence is a property of atoms that refers to their ability to bond with other atoms. Whether through ionic or covalent bonds, most atoms have the ability to bond together to create various elements.
The ability to bond between atoms varies depending on the atom. The number of possible bonds between atoms changes according to the type of atom. Some atoms such as helium, neon, argon, krypton, xenon and radon have valences of 0. This means that they cannot bond to other atoms. This is why they are categorized as noble gases in the periodic table.
Depending on the number of possible bonds by the atom, the atoms are called monovalent, divalent, trivalent, etc. In short, we will say that an atom has a valence of 3 when it is trivalent.
In general, valence is measured in terms of the number of electrons that the atom can receive or give.