What is valency in terms of chemistry?

Valency in chemistry refers specifically to the number of electrons that an atom can gain, lose, or share during a chemical reaction to form bonds with other atoms. It is a measure of an atom's ability to combine with other atoms, which essentially reflects the involvement of electrons in creating chemical bonds.

While protons determine the identity and position of an element in the periodic table, they do not directly define an atom's bonding capacity. The ability to conduct electricity is more related to the presence of free-moving ions or electrons in a solution rather than valency itself. Additionally, the mass comparison to carbon-12 relates to atomic mass but not to the concept of valency. The concept of valency is fundamentally centered around the behavior of the outermost electrons, which are key to forming molecules and compounds.