Class 5 Science - Air and Water - CBSE Worksheets Solutions - 1

Q1: Multiple Choice Questions (MCQs).

(ii) What is the main source of water on Earth?
(a) Lakes
(b) Rivers
(c) Rain
(d) Groundwater
Ans: (c)
Rain is the main source of water on Earth as it replenishes rivers, lakes, and groundwater, which are also sources of water.

(iii) Water pollution can be caused by:
(a) Sewage
(b) Industrial waste
(c) Oil spills
(d) All of the above
Ans: (d)
Water pollution can be caused by sewage, industrial waste, oil spills, and other contaminants that harm the quality of water.

(iv) Which of the following is a renewable source of energy?
(a) Coal
(b) Oil
(c) Wind
(d) Natural gas
Ans: (c)
Wind is a renewable source of energy because it is continuously replenished by the Earth's natural processes, unlike coal, oil, and natural gas, which are finite resources.

(v) Which of the following is NOT a property of water?
(a) It is tasteless
(b) It is colorless
(c) It is odorless
(d) It is a gas
Ans: (d)
Water is a liquid at room temperature. It is tasteless, colorless, and odorless.

Q2: Fill in the blanks.

(ii) The process by which water vapor changes into water droplets is called ___________.
Ans: The process by which water vapor changes into water droplets is called Condensation.

(iii) The process of changing a liquid into a gas is called ___________.
Ans: The process of changing a liquid into a gas is called Evaporation.

(iv) -The process by which water is replenished in the atmosphere is called ___________.
Ans: The process by which water is replenished in the atmosphere is called Evaporation.

(v) The process of turning water into a solid is called ___________.
Ans: The process of turning water into a solid is called Freezing.

Q3: Match the column.

Ans: (i) Oxygen - D. The component of air that supports combustion
(ii) Evaporation - A. The process of changing a liquid into a gas
(iii) Condensation - B. The process of changing water vapor into water droplets
(iv) Freezing - C. The process of turning water into a solid

Q4: True or False.

(ii) Air pollution has no effect on human health.
Ans: False
Air pollution can have severe effects on human health, including respiratory problems, heart disease, and even cancer.

(iii) The boiling point of water is 100 degrees Celsius.
Ans: True
The boiling point of water is 100 degrees Celsius. At this temperature, water changes from a liquid to a gas.

(iv) Oxygen is the most abundant gas in the atmosphere.
Ans: False
Oxygen is not the most abundant gas in the atmosphere – nitrogen is. Nitrogen makes up about 78% of the Earth's atmosphere, while oxygen accounts for about 21%.

(v) The process by which water is replenished in the atmosphere is called evaporation.
Ans: True
The process by which water is replenished in the atmosphere is called evaporation. Water evaporates from the Earth's surface and rises into the atmosphere, where it can later fall back to Earth as precipitation.

Q2: Short Answer Questions.

(ii) Explain the water cycle.
Ans: The water cycle is the process by which water evaporates from the Earth's surface, forms clouds, and then falls back to the ground as precipitation. This cycle helps to maintain the Earth's water supply.

(iii) What is the role of air in the Earth's atmosphere?
Ans: Air plays a significant role in the Earth's atmosphere by providing us with oxygen to breathe, protecting us from harmful solar radiation, and acting as a blanket to keep the Earth's temperature stable.

(iv) How can we conserve water at home?
Ans: We can conserve water at home by using water-saving appliances, fixing leaks, turning off the tap when not in use, and repurposing water when possible (e.g., using rainwater for plants).

(v)  What are the effects of air pollution on the environment and human health?
Ans: Air pollution can have severe effects on the environment and human health. It can cause respiratory problems, heart diseases, and even cancer in humans. Additionally, air pollution can harm plants and animals, damage buildings, and contribute to climate change.