Question

Which of the following is not a compound ?
A. Sugar
B. Ozone
C. Benzene
D. Salt

Answer 1

A compound is a pure substance containing two or more than two elements combined together in a fixed proportion by mass and which can be decomposed into its constituent elements by suitable chemical methods .

Complete step by step answer:
Let us first examine each of the molecules given in the options :
Sugar - Sugar is a molecule which has carbon , hydrogen and oxygen atoms as its constituent elements, its chemical formula is ${C_6}{H_{12}}{O_6}$ , hence , it contains more than one type of atoms and is a compound .
Ozone - The chemical formula of ozone is ${O_3}$ . As we can see it contains only oxygen atoms. Hence it is not a compound as it contains only one kind of element .
Benzene - Benzene is an aromatic compound consisting of carbon and hydrogen with the chemical formula ${C_6}{H_6}$ . Therefore , it is a compound since it contains two different atoms.
Salt - Salt is sodium chloride that is , $NaCl$ . It is also a compound since it has sodium and chlorine as its constituent elements .
Hence , it is clear that ozone is not a compound .

So, the correct answer is Option B.

Note: The constituents of a compound are always present in fixed ratio by mass and they are homogeneous in nature . Their properties are entirely different from those of its constituents and cannot be separated by simple mechanical means .