Question

The atomicity of Na is 1. What does it mean?

• A. It can combine with only one element.
• B. It exists as a single atom, unlike molecules.
• C. Both A and B
• D. The statement is incorrect. Its atomicity is 2.

Answer 1

The correct option is B

It exists as a single atom, unlike molecules.

Atomicity is the total number of atoms present in one molecule of an element, compound or a substance. Monoatomic - consist of 1 atom, diatomic - consists of 2 atoms, triatomic - consists of 3 atoms and polyatomic - consists of more than 3 atoms. For example, in $H_2$, there are 2 atoms of hydrogen, hence it is a diatomic molecule.

Here, in $Na$, since there is only one atom present so its atomicity is 1 and hence it is monoatomic.