Which one of the following is not electronic configuration of a noble gas ?

Correct option is B

Ans.(b) 2,8,18,2

Explanation:
The correct answer is 2,8,18,2. Noble gases have fully filled outermost electron shells, making them chemically inert. The configuration 2,8,18,2 belongs to Calcium (Ca), which is not a noble gas. Noble gases follow the octet rule, meaning their outermost shell is completely filled, ensuring stability and non-reactivity.

Information Booster:
● Noble gases include Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).
● They have stable valence electron configurations (duplet for He, octet for others).
● Due to their inert nature, noble gases are used in lighting, welding, and cooling applications.
● Their lack of reactivity makes them ideal for use in gas-filled lamps and scientific equipment.
● Helium is the lightest noble gas, used in airships and balloons.
● Xenon is used in high-intensity discharge lamps and medical imaging.
● Noble gases occur naturally in the atmosphere in trace amounts.