Question

The substances which easily catch fire in air or oxygen are called,

• A. flammable substances
• B. combustible substances
• C. either (A) and (B)
• D. heat sensitive substances

Answer 1

The correct option is C

either (A) and (B)

Explanation for correct answer:

Option (C):

1. Combustion: Chemical process in which a substance reacts with oxygen to give off heat is called combustion.
2. When substances react spontaneously with oxygen giving off heat and light.
3. The lowest temperature at which a substance catches fire is called its ignition temperature.
4. The substances which have very low ignition temperature and can easily catch fire with a flame are called flammable or combustible substances.
5. Ex: petrol, LPG, etc.
6. Hence, the substances which easily catch fire in air or oxygen are called: flammable substances or combustible substances.

Thus, the correct option is option (C).