Question

How are molecules classified based on their atomicity? Give examples.

Answer 1

Part 1: Atomicity -

• It is defined as the total number of atoms present in a molecule.
• For example- Each molecule of oxygen is composed of two oxygen atoms. So atomicity of oxygen is 2

Part 2: Atomicity is based on the number of molecules composed-

Monoatomic molecules-

• It contains only one atom like helium $\left(\mathrm{He}\right)$ neon $\left(\mathrm{Ne}\right)$.
• They are basically noble Gas.

Diatomic molecules-

• They contain two atoms in molecules.
• Example- chlorine as ${\mathrm{Cl}}_2$ , Hydrogen as ${\mathrm{H}}_2$etc.

Triatomic molecules-

• They contain three atoms in molecules.
• Example- Ozone as 3 oxygen atoms which is written as ${\mathrm{O}}_3$.

Polyatomic molecules-

• They contain more than 3 atoms in the molecules.
• Example- phosphorous as ${\mathrm{P}}_4$; Hexene $\left({\mathrm{C}}_6{\mathrm{H}}_6\right)$