Question

11. A material A can exist in three physical i.e. solid, liquid, and gas. No living thing on earth can exist in the absence of this material. It falls from the clouds in the form of B. Lack of B for long period in an area may cause C whereas an excess of B may cause D.

(a) What are A, B, C, and D?

Answer 1

Part 1:

• According to the given information, A can exist in three physical states i.e. solid, liquid, and gas, and no living thing on earth can exist in the absence of this material.
• Therefore, the given material is water because it also exists in three states i.e ice (solid), water (liquid), and water vapor (gas), and also without water, no living thing on earth can survive.
• Hence, A is water.

Part 2:

• According to the given information, A (water) falls from the clouds in the form of B.
• Therefore, water i.e. A falls from the cloud in the form of rainwater.
• Hence, B is rainwater.

Part 3:

• According to the given information, lack of B i.e. rainwater for long period in an area may cause C.
• A prolonged period of no rains or very low rains causes an all-round shortage of water leading to drought.
• Hence, C is drought.

Part 4:

• According to the given information, excess of B i.e. rainwater may cause D.
• When there is an excess of rainwater then water in the rivers may rise above their banks and flow into the nearby land. Such condition is known as floods.
• Hence, excess of B i.e. rainwater may cause D which is the flood.