Question

What is the formula for finding the atomicity of an atom or element?

Answer 1

Hint: The mass of individual atoms and molecules is defined by the atomic mass unit (u). The sum of the masses of the atoms in a molecule is the molecular mass.

Complete answer:
The total number of atoms that make up a molecule is known as atomicity. Simply stated, it refers to the number of atoms in a molecule. If you know the atomic mass and number of atoms in the molecule of the element whose atomicity you want to find, you can easily determine its atomicity. Different allotropes of the same element may have different atomicities.
 For example, you know that oxygen has an atomic mass of $$16$$ and that its molecule contains two atoms ( $${\text{O}}_{\text{2}}$$), so its molecular mass is $$32$$. Remove the ratio, and the result would be$$2$$. Similarly, an ozone molecule ($$O_3$$) is made up of three oxygen atoms and has an atomicity of three. Alternatively, counting the number of atoms in a molecule is a straightforward way to determine atomicity. $$H_2$$ has two atoms of hydrogen in its molecule, so its atomicity is two.
As a result, atomicity of an element=molecular mass/atomic mass. This relationship can also be used to determine the atomicity of other elements.

Note:
Metals and some other elements, such as carbon, do not have a basic structure; instead, they are made up of an infinite number of atoms that are bound together. Their atomicity can't be calculated, so it's usually assumed to be $$1$$.