A molecule is formed by the chemical combination of atoms. It is the smallest unit of a substance. It shows all the properties of the sbstance and can exist independently. There are different types of molecules depending upon the number and types of atoms combining. A few types are disscused here.
- A molecule consisting only one atom is called monoatomic molecule . For example, the innert gases helium, neon and argon all exist independently in atomic form and they are called monoatomic molecules.
- If a molecule consists of two atoms, is called diatomic molecule. Fo example: Hydrogen (H2), oxygen (O2), Chlorine(Cl2) and hydrogen chloride(HCl).
- If it consists of three atoms, it is called triatomic molecule. For example H2O and CO2.
- If a molecule consists of many atoms, it is called polyatomic molecule. For example, methane (CH4), sulphuric acid (H2SO4) and glucose (C6H12O6).
- A molecule containing same type of atoms, is called homoatomic molecule. For example, hydrogen (H2), ozone (O3), sulphur (S8) and phosphorus (P4) are the examples of molecules by the same type of atoms.
- When a molecule consists of different kind of atoms, it is called hetero-atomic molecule. For example: CO2, H2O and NH3.