The valency chart consists of a complete list of the valencies of that element. The chemical formula of an element is determined on the basis of the valencies of its compound. Valency can be defined as the combining capacity of an element. It is always a whole number and does not have a plus or minus sign. The electrons present in the outermost shell of an atom are known as valence electrons, and so in that context, valency can be defined as the number of electrons an element can lose or gain to attain stability.
When constructing the chemical formula of a compound, a valency chart is used, which implies that by using the valency, it is possible to determine how the atoms of one element will mix with the atoms of another element.
