Question

Which of the following is monoatomic molecule?

• A. He
• B. H
• C. Cl₂
• D. O₂

Answer 1

The correct option is B

H

Explanation for the correct option

a) Molecules of some elements consist of only one atom. Their atomicity is said to be 1 and they are called monoatomic. For example, all noble gases such as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) are monoatomic.

Explanation for the incorrect option

The molecules of certain elements consist of two atoms of the same elements. Their atomicity is 2 and they are called diatomic molecules. For example, the elements hydrogen (H₂ ), nitrogen (N₂), chlorine (Cl₂), and oxygen (O₂) have diatomic molecules.

Hence, option (a) is correct, He is monoatomic molecule.