GSEB Class 6 Science Solutions Chapter 14 Water

Question 1. Fill up the blanks in the following:
(a) The process of changing of water into its vapour is called ______.
(b) The process of changing water vapour into water is called ______.
(c) No rainfall for a year or more may lead to ______ in that region.
(d) Excessive rains may cause ______.

Answer:
(a) evaporation or vaporisation
(b) condensation
(c) droughts
(d) flood

Exam Tip: Remember the basic definitions for each blank and how they relate to the water cycle and weather conditions.

Question 2. State for each of the following whether it is due to evaporation or condensation:
(a) Water drops appear on the outer surface of a glass containing cold water.
(b) Steam rising from wet clothes while they are ironed.
(c) Fog appearing on a cold winter morning.
(d) Blackboard dries up after wiping it.
(e) Steam rising from a hot girdle when water is sprinkled on it.

Answer:
(a) condensation
(b) evaporation
(c) condensation
(d) evaporation
(e) evaporation
In simple words: When water turns into vapor, it's evaporation. When vapor turns back into liquid, it's condensation. Cold surfaces make water vapor condense, while heat makes water evaporate faster.

Exam Tip: Focus on whether water is changing from liquid to gas (evaporation) or gas to liquid (condensation) for each scenario.

Question 3. Which of the following statements are “true”?
(a) Water vapour is present in air only during the monsoon.
(b) Water evaporates into air from oceans, rivers and lakes but not from the soil.
(c) The process of water changing into its vapour is called evaporation.
(d) The evaporation of water takes place only in sunlight.
(e) Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.

Answer:
(a) False
(b) False
(c) True
(d) False
(e) True.
In simple words: Water vapor is always in the air, not just during monsoon. Water evaporates from many places, including soil. Evaporation doesn't only happen in sunlight. Condensation does form droplets in cooler air.

Exam Tip: Understand the continuous nature of the water cycle and the conditions under which evaporation and condensation occur.

Question 4. Suppose you want to dry your school uniform quickly. Would spreading it near an anghiti or heater help you? If yes, how?

Answer: Yes, to dry the school uniform quickly, the uniform could be spread near an anghiti or heater because evaporation is rapid at higher temperature. The higher the temperature, the faster the rate of evaporation. So the uniform is dried up quickly.
In simple words: Yes, a heater or anghiti helps dry clothes faster. Heat makes water turn into vapor more quickly, so the clothes dry quickly.

Exam Tip: When explaining evaporation, always connect it to factors like temperature, surface area, and humidity, as these influence the rate.

Question 5. Take out a cooled bottle of water from refrigerator and keep it on a table. After some time you notice a droplets of water around it. Why?

Answer: The cooled water bottle has a very cold exposed surface. Because of this cool surface, there is condensation of water-vapour from the air on the bottle's surface, as water vapour is present in the atmosphere. The condensed water molecules spread around the bottle. So, a puddle of water is noticed after some time.
In simple words: The cold bottle cools the air around it. Water vapor in the air then changes into liquid water droplets on the bottle's surface.

Exam Tip: This question tests your understanding of condensation. Key terms to use are "cold surface," "water vapour," and "condensation."

Question 6. To clean their spectacles, people often breathe out on glasses to make them wet. Explain why the glasses become wet?

Answer: The exhaled gases contain water-vapour. This water-vapour condenses on the spectacles, making the glass wet. With the help of this small amount of water, it is easy to clean the spectacles.
In simple words: Our breath has water vapor. When this warm vapor hits the cooler spectacle lenses, it condenses into tiny water droplets, making them wet.

Exam Tip: Remember that exhaled breath is warm and humid, and cooler surfaces cause the water vapor in it to condense into liquid. This principle applies to fogging mirrors too.

Question 7. How are clouds formed?

Answer: The water present on the earth evaporates due to heating by the sun. The water vapour in the air condenses to form tiny droplets of water at high altitude, which appears as clouds. Thus clouds are formed by the condensation of water vapours present in air at high altitude.
In simple words: The sun heats water on Earth, turning it into vapor. This vapor rises high into the sky, cools down, and changes back into tiny water droplets, which we see as clouds.

Exam Tip: Focus on the sequence: evaporation from Earth's surface, rising water vapor, cooling at high altitudes, and finally, condensation to form droplets.

Question 8. When does a drought occur?

Answer: If there is no rain for a long period or for many years, then there is a scarcity of water in that region. This leads to drought.
In simple words: A drought happens when it doesn't rain for a very long time, causing a severe shortage of water in an area.

Exam Tip: Define drought as a prolonged period of insufficient rainfall, leading to water scarcity and its associated impacts.