Explain:
Inert gases.

Inert gases:

• Elements of group 18 are gases and non-reactive due to completely filled outermost orbital.
• So, due to their high stability and non-reactive nature, they are known as inert gases.
• Also, known as Noble gases namely Helium(He), Neon(Ne), Argon(Ar), etc.
• Inert gases are generally colourless, odourless and tasteless, and non-inflammable gas.
• They are present in air in very lesser amounts.