Question

Which one of the following is a compound?

• A. The black residue left when sugar is charred
• B. Nitrogen gas
• C. Air
• D. Carbon dioxide

Answer 1

The correct option is D Carbon dioxide

Among these only carbon dioxide is a compound.

Compound is a substance formed from two or more elements chemically bonded in a definite proportion.

Example- Carbon dioxide, water, glucose, etc.

In the given options,

A- the black residue that is left after charring sugar is carbon. Carbon is an element in pure state.

B- Nitrogen gas is a molecule as it is composed of only one element ie., Nitrogen so this can't be termed as a compound.

C- Air is a homogeneous mixture of different gases.