Answer: Option (b) is the correct answer.
Explanation:
A compound is defined as a substance that has two or more number of different atoms which are chemically combined to each other in a fixed ratio by mass.
For example, [tex]H_{2}O[/tex] contains two atoms of hydrogen and one atom of oxygen which are chemically combined together in 2:1 ratio. Therefore, it is a compound.
On the other hand, if a substance contains only atoms of one type of element then it is known as a molecule.
For example, [tex]C_{2}[/tex], [tex]H_{2}[/tex], and [tex]O_{2}[/tex] are all molecules.
Thus, we can conclude that out of the given options [tex]H_{2}O[/tex] represents a compound.
