Define homoatomic and heteroatomic molecules.
Homoatomic molecules: These are the molecules which are made up of atoms of the same element. Most of the elementary gases consist of homoatomic molecules. For example, hydrogen gas consists of two atoms of hydrogen (H2). Similarly, oxygen gas consists of two atoms of oxygen (O2). In accordance with the number of atoms present in these molecules they are classified as monoatomic, diatomic, triatomic or polyatomic molecules showing that they contain one, two, three or more than three atoms respectively.
For any homoatomic molecule, atomicity can be deduced using the formula:
Atomicity = Molecular massAtomic mass
Heteroatomic Molecules: The heteroatomic molecules are made up of atoms of different elements. They are also classified as diatomic, triatomic, or polyatomic molecules depending upon the number of atoms present. H2O,NH3,CH4 etc. are the examples of heteroatomic molecules.