[1] In older contexts, atomicity is sometimes equivalent to valency.
Some authors also use the term to refer to the maximum number of valencies observed for an element.
The exact atomicity of metals, as well as some other elements such as carbon, cannot be determined because they consist of a large and indefinite number of atoms bonded together.
It depends on the type of bonding the atom makes with itself to form the molecule of that particular element.
The most common values of atomicity for the first 30 elements in the periodic table are as follows: