Question

Which of the following element is inert ?

• A. Fe
• B. He
• C. Cl
• D. Ag

Answer 1

Answer: (B)

He

Inert elements are chemically stable elements with stable fully filled outer electronic configuration and thus do not have the affinity to participate in a reaction. Example: helium[$1s^2$] , neon[$1s^{2}2s^{2}2p^6$] .