Question

B. Statements given below are incorrect. Write the correct statement:

1. The smallest unit of a pure substance is called an atom.

Answer 1

• The smallest particle of a pure substance that always exists independently and can retain all the physical and chemical properties of that substance is called a molecule.
• Atom is the smallest particle of an element, which may or may not have an independent existence, but always take part in a chemical reaction.

Hence, the given statement is incorrect as the smallest unit of a pure substance is called a molecule.