Question

Which of the following is an inert gas ?

• A. $H_2$
• B. $O_2$
• C. $N_2$
• D. Argon

Answer 1

Answer: (D)

Elements belonging to the $18^{\text{th }}$ group of modern periodic table are known as inert gases or noble gases. Their general electronic configuration is $n{s}^2{p}^6$. They are called so because they have eight electrons (Octet) in their outermost shell (except Ile which has $2$ electrons) due to which they are unreactive i.e., no tendency to lose or gain or share electrons. Besides hydrogen has got $1$ electron oxygen bas $6$ electrons and nitrogen has $5$ electrons in the gutermost shelll, which cause them to react and form $H_2,N_2$ and $O_2$ molecules. All inert gases are monoatomic $i.e.$, have only one atom in their molecule.