Assertion (A): Ozone is an example of a molecule of an element.​

Reason (R): Molecules formed by different kind of atoms is known as molecule ​of an element.​

(a) What is an atom ? How do atoms usually exist?

(b) What is a molecule? Explain with an example.

(c) What is the difference between the molecule of an element and the molecule of a compound ? Give an example of each.

When an atom of an element joins with another atom or atoms of the same element, a molecule of an ______________ is formed.

Assertion (A) : Ammonia (${\text{NH}}_3$) is an example of a molecule of an element.​

Reason (R) : Molecules formed by same kind of atoms is known as molecule ​of an element.