Question

Define homo atomic and heteroatomic molecules.

Answer 1

Hint: Homo means only one type and hetero means more than one type. Some examples of homo atomic molecules are hydrogen gas, oxygen gas, nitrogen gas, phosphorus molecule, etc and some examples of heteroatomic molecules are water, methane, hydrochloric acid, etc.

Complete answer:
We know that molecules and compounds are made up of atoms of the elements. In a molecule, there can be any number of atoms and they are diatomic, triatomic, tetra-atomic, poly-atomic, etc.
So, based on the type of atoms in the molecules, there are two types of molecules, i.e., Homo atomic molecules and Hetero atomic molecules. Homo means only one type and hetero means more than one type.
 Homo atomic molecules can be defined when the molecules contain only one type of atom. Examples of homo atomic molecules are hydrogen gas (${{H}_{2}}$), oxygen gas (${{O}_{2}}$), nitrogen gas (${{N}_{2}}$), phosphorus molecule (${{P}_{4}}$), etc.
Hydrogen gas, oxygen gas, nitrogen gas are also examples of diatomic molecules, phosphorus molecules are examples of a tetra-atomic molecule.
Hetero atomic molecules can be defined as when the molecule contains more than one type of atom. Examples of heteroatomic molecules are water (${{H}_{2}}O$), methane ($C{{H}_{4}}$), hydrochloric acid (HCl), etc
Hydrochloric acid is also an example of a diatomic molecule, water is an example of a tri-atomic molecule, and methane is an example of a polyatomic molecule.

Note:
By using the atomic mass and the molecular mass we can easily find the atomicity. Atomicity is the ratio of molecular mass and atomic mass. It is given as:
$Atomicity=\dfrac{Molecular\text{ }mass}{Atomic\text{ }mass}$