Atomicity (chemistry)

Atomicity is the total number of atoms present in one molecule of an element, compound or a substance.For example in O2 there are 2 atoms of oxygen.

Example

Consider

[Hydrogen (H2) = atomicity is 2],

[Ozone (O3) . . . = atomicity is 3],

[Phosphorus (P4) = atomicity is 4]

As I told you before that the number of atoms present in one molecule of an element is called its atomicity.

Monoatomic, diatomic ,triatomic and Polyatomic

These all means just how many atoms are present in one molecule. For example =

Helium(He)=it has atom present in its one molecule so it is called monoatomic.

Hydrogen (H2) = it has 2 atoms present in its one molecule so it is called diatomic.

Ozone (O3) = it has 3 atoms present in its one molecule so it is called triatomic.

Likewise the no. Of atoms present in one molecule have different atomicity.

For=

1= Monoatomic

2= diatomic

3= triatomic

4= tetra-atomic

more than 4=polyatomic

8= Octa-atomic

Noble gases

A molecule which contains only one atom is called monatomic (inert gases), A molecule which contains two atoms is called diatomic (oxygen, nitric oxide, hydrogen, etc.) and A molecule containing three atoms is called a triatomic moleculele (ozone, sulphur dioxide, carbon dioxide,etc.)and A molecule containing more than 3 atoms are known as a polyatomic ions (phosphate,sulphur,etc.)