Question

Which of these is a compound? A. Steel B.Sugar C.Air D.Nitrogen

Answer 1

Sugar is a compound made of carbon, hydrogen and oxygen.

Answer 2

Answer: The correct option is B.

Explanation:

An element is the simplest substance which cannot be divided further and is made up from only one type of atoms. Example: oxygen, nitrogen etc.

A compound is defined as a substance which is formed by the combination of two or more elements in a fixed ratio. Example: $CO_2,H_2O$ etc.

A mixture is formed by the combination of elements or compounds in a non-uniform ratio. Example: Salt in water

Option A: Steel is a alloy of 96% iron, carbon and many other elements. This is a homogeneous mixture of more than 2 elements. Hence, it is considered as a mixture because elements are not present in a fixed ratio.

Option B: Formula for sugar is $C_{12}H_{22}O_{11}$. This is a compound made from the elements: Carbon, Hydrogen and Oxygen in a fixed ratio of 12 : 22: 11. Hence, it is considered as a compound.

Option C: Air is a mixture of many gases. Gases present in air are nitrogen, oxygen, argon , carbon dioxide etc. These gases are not present in fixed ratio.

Option D: Nitrogen is the simplest unit of substance. It is considered as an element.

Hence, the correct option is B.