Fill in the blanks in the following sentences.

(a) Coal is one of the ________ used to cook food.

(b) When heated in air, coal burns and produces mainly ________ gas.

(c) Coal tar is a black, thick ________ with an ________ smell.

(d) Petroleum, ________ and ________ are fossil fuels.

(e) Forests and coal are ________ natural resources.

a) Fuels

Coal produces heat energy when burnt so it can be used as a good fuel to cook food.

b) Carbon dioxide

Coal is a form of carbon so when it burns in air, it reacts with oxygen to form carbon dioxide gas.

c) liquid, unpleasant

Coal tar is one of the products of coal which is a black, thick fluid having unpleasant smell which is used for metalling roads.

d) Coal, natural gas

They are fossil fuels as they are obtained from dead remains of plants, animals.

e) Exhaustible

They are present in limited quantity in nature and can be exhausted by human activities.