Class 5 Science - Air and Water - Question Answers

Q1: Explain what the atmosphere is and why it is essential for life on Earth.
Ans: The atmosphere is a thick layer of air surrounding the Earth, like a blanket. It's essential for life because it provides the air we breathe, protects us from harmful rays from the sun, and plays a crucial role in weather changes.

Q2: Describe the layers of the atmosphere and their unique features.
Ans: The atmosphere has layers like troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Each layer has different properties and functions. The troposphere is where weather changes occur, and clouds are formed, while the stratosphere has the ozone layer protecting us from harmful rays.

Q3: Explain the composition of air. How does air pressure work, and what are its everyday uses?
Ans: Air is mainly made up of nitrogen (about 78%) and oxygen (about 21%). Other gases make up the remaining 1%. Air pressure is the force exerted by air. It is used in everyday activities like sipping drinks through straws and inflating vehicle tires.

Q4: Why is nitrogen important even though we don't use it directly from the air? Explain its role in the atmosphere.
Ans: Nitrogen is essential for plants and animals. Plants get nitrogen from the soil, and animals get it from plants or meat. It supports plant growth and ensures a balanced ecosystem.

Q5: Describe how air helps in the water cycle and the importance of the water cycle for life on Earth.
Ans: The atmosphere helps in the water cycle by allowing water to evaporate from the surface and form clouds. Rainfall and precipitation occur due to this cycle, providing us with fresh water essential for life.

Q6: Explain the properties of water and its states of matter. Why is water known as the universal solvent?
Ans: Water has no color, taste, or odor and can exist in solid, liquid, or gas states. It's called the universal solvent because it dissolves many substances due to its unique properties.

Q7: Discuss the impurities in water and methods to remove them. Why is it crucial to remove impurities from drinking water?
Ans: Impurities in water can be soluble (dissolved salts) or insoluble (sand, mud). They can be removed through sedimentation, decantation, filtration, evaporation, or distillation. Removing impurities is essential to make water safe and clean for drinking, preventing diseases.

Q8: Describe the importance of water for living beings. How is water distributed on Earth's surface?
Ans: Water is crucial for all living beings for drinking, cooking, bathing, and more. About 71% of Earth's surface is water, with most of it in the oceans (salty), glaciers (frozen), and a small percentage as fresh water in rivers, lakes, and ponds.

Q9: Explain how water's unique properties allow it to move through plants and blood vessels in our bodies.
Ans: Water's tendency to clump together in drops allows it to move through plants' roots and stems, delivering nutrients. In our bodies, it moves through tiny blood vessels, aiding in various bodily functions.

Q10: Describe the methods to purify drinking water and their importance in maintaining good health.
Ans: Boiling, chlorination, and water filters are common methods to purify drinking water, ensuring it's safe to consume by killing germs and removing impurities. Clean water is essential for preventing diseases and maintaining good health.