Difference between atomicity and atomic number

 

 

It is the total number of atoms present in one molecule of an element or a compound. 

For example: 

One molecule of hydrogen (H₂) contains two atoms of hydrogen. Therefore, atomicity of hydrogen is 2.

 

 

Atomic number of an neutral atom of an element is equal to the number of electrons or protons in an atom, because in a neutral atom number of electrons equal to number of protons. It is denoted by 'Z'.

Atomic number = Number of protons or number of electrons

For Example:

A hydrogen atom contains 1 proton, so its atomic number is 1.

 

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