Question

Which of the following are molecules of elements?

• A. Ozone
• B. Nitrogen
• C. Carbon monoxide
• D. Water

Answer 1

Answer: (A), (B)

The correct options are
A Ozone
B Nitrogen

Atoms of same or different elements combine in definite proportions to form molecules. Given below are few molecules along with their constituent atoms.
$$\begin{array}{cc}\text{Molecule}& \text{Constituent Atoms}\\ \text{Ozone (}{O}_3\text{)}& \text{3 O}\\ \text{Nitrogen (}{N}_2\text{)}& \text{2 N}\\ \text{Water (}{H}_{2}O\text{)}& \text{2 H, 1 O}\\ \text{Carbon monoxide (}CO\text{)}& \text{1 C, 1 O}\end{array}$$
Molecules of elements have only one kind of atom in them. Among the given options, only ozone and nitrogen are molecules of elements.