Atomicity
The number of atoms of all the
elements present in a molecule of any substance is called its atomicity.
Monatomic molecules.
The molecules which contain only
one atom in their molecule are called monatomic molecules.
Examples. Noble gases viz,
helium, neon, argon, etc. are monatomic gases. Therefore, the atomicity of
helium (He), neon (Ne) and argon (Ar) is one.
Diatomic molecules.
The molecules which contain two
atoms in their molecule are called diatomic molecules.
Examples. The molecules of gases
like hydrogen, oxygen, nitrogen, chlorine, etc. contain two atoms. Therefore, molecules
of hydrogen, oxygen, nitrogen, chlorine are diatomic molecules.
Thus, the atomicity of hydrogen
(H2), oxygen (O2), nitrogen (N2) and chlorine
(Cl2) is two.
Triatomic molecules.
The molecules which contain
three atoms in their molecule are called triatomic molecules. Examples. The
molecules of water and carbon dioxide are triatomic molecules. Therefore, the
atomicity of water (H2O) and carbon dioxide (CO2) is
three.
The atomicity of
• Ozone is 3
• Phosphorus (yellow) is 4
• Sulphur is 8
