Indicate whether the following statements are True or False. Also write the false statements in their correct form.

(a) Air is necessary for combustion.

(b) Magnesium is a non-combustible metal.

(c) Carbon dioxide is an excellent fire extinguisher.

(d) Calorific value of wood is higher than that of coal.

Statement (a) is correct.

Air consists of oxygen which is a necessity for ignition.

Statement (b) is wrong. The correct statement is - Magnesium is a combustible metal.

Magnesium has an ability to catch fire and thus burn easily. It burns as soon as it is ignited.

Statement (c) is correct.

Carbon di oxide helps extinguish fire by taking away the oxygen, thus making it difficult for the substance to continue to burn.

(d) is wrong. The correct statement is - Calorific value of coal is higher than that of wood.

More Calorific value of Coal represents that coal is more efficient than wood.