Class 6 Science Chapter – Water Notes

Introduction: Water is one of the most important natural resources on Earth. It is essential for the survival of all living beings. Every organism – plants, animals, and humans – depends on water. In this chapter, we will study the sources of water, its uses, forms, importance, and methods of conservation.

Class 6 Science Chapter Water Notes and Question Answer with NCERT Solutions, MCQ, Short and Long Questions
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Sources of Water

Water is available from both natural and man-made sources. Major sources include rain, rivers, lakes, ponds, wells, and groundwater. Rain is considered the primary source of all freshwater. The water from rainfall flows into rivers, lakes, and underground reserves, which are later used by humans and other organisms.

Uses of Water

Water is used in many ways such as drinking, cooking, cleaning, irrigation, electricity generation, and industrial purposes. Farmers use a large quantity of water for irrigation of crops. Industries use water to produce goods. Without water, human activities cannot be carried out smoothly.

Forms of Water

Water exists in three states:

  • Solid: Ice and snow.
  • Liquid: Water in rivers, lakes, ponds, and oceans.
  • Gas: Water vapor in the atmosphere.

Water Cycle

The circulation of water from the Earth's surface to the atmosphere and back is called the water cycle. The main processes are evaporation, condensation, and precipitation. Evaporation from oceans, lakes, and rivers forms clouds. These clouds bring rainfall, which replenishes rivers, lakes, and groundwater.

Groundwater

A major portion of water that we use comes from underground sources. Wells, handpumps, and tube wells are examples of groundwater usage. It is stored below the surface in spaces between soil particles and rocks, known as aquifers.

Water Scarcity

In many regions, people face shortage of water due to overuse, wastage, uneven rainfall, or pollution of water sources. This is known as water scarcity. It can affect farming, daily needs, and health.

Water Conservation

We must use water carefully. Some methods to conserve water include:

  • Close taps when not in use.
  • Repair leaking pipes.
  • Use rainwater harvesting systems.
  • Avoid wasting water during daily activities.

Key Notes

  • Water is essential for all forms of life.
  • Sources: Rain, rivers, lakes, ponds, and groundwater.
  • Water cycle maintains balance in nature.
  • Water scarcity is a serious problem in many places.
  • Conservation of water is our responsibility.

Class 6 Science Chapter – Water Questions & Answers

Multiple Choice Questions (MCQs)

  1. Which is the primary source of freshwater?
    a) Oceans
    b) Rain
    c) Rivers
    d) Groundwater
    Answer: b) Rain
  2. Water in the form of vapor is present in:
    a) Rivers
    b) Lakes
    c) Atmosphere
    d) Ice
    Answer: c) Atmosphere
  3. The process of changing water into vapor is called:
    a) Condensation
    b) Evaporation
    c) Precipitation
    d) Freezing
    Answer: b) Evaporation
  4. Handpumps and wells are examples of:
    a) Rainwater
    b) Surface water
    c) Groundwater
    d) Ocean water
    Answer: c) Groundwater
  5. Which of the following is a method of water conservation?
    a) Wasting water
    b) Rainwater harvesting
    c) Polluting rivers
    d) Cutting trees
    Answer: b) Rainwater harvesting
  6. The circulation of water between earth and atmosphere is called:
    a) Water flow
    b) Water storage
    c) Water cycle
    d) Water scarcity
    Answer: c) Water cycle
  7. Which one is NOT a form of water?
    a) Solid
    b) Liquid
    c) Gas
    d) Metal
    Answer: d) Metal

Very Short Answer Questions

  1. What is the main source of water on Earth?
    Answer: Rain.
  2. Name any two sources of groundwater.
    Answer: Wells and handpumps.
  3. In which three forms does water exist?
    Answer: Solid, liquid, and gas.
  4. What is the process of water vapor changing into liquid called?
    Answer: Condensation.
  5. Name one method of water conservation.
    Answer: Rainwater harvesting.
  6. What is the underground water storage called?
    Answer: Aquifer.
  7. What is the importance of water for plants?
    Answer: It helps in photosynthesis and growth.

Short Answer Questions

  1. Why is rain called the main source of water?
    Answer: Rainfall replenishes rivers, lakes, ponds, and groundwater, which are the primary sources of freshwater for living beings.
  2. Write any three uses of water.
    Answer: Drinking, irrigation, and electricity generation.
  3. What is the water cycle?
    Answer: The continuous circulation of water from the earth’s surface to the atmosphere and back through evaporation, condensation, and precipitation.
  4. Give two reasons for water scarcity.
    Answer: Overuse of water and uneven rainfall.
  5. How can leaking taps cause water wastage?
    Answer: Continuous dripping wastes liters of water daily, leading to shortage over time.
  6. Why is groundwater important?
    Answer: It provides water for drinking, irrigation, and daily use when surface water is not available.
  7. Write two advantages of rainwater harvesting.
    Answer: It stores rainwater for later use and helps recharge groundwater levels.

Long Answer Questions

  1. Explain the importance of water in our daily life.
    Answer: Water is necessary for drinking, cooking, cleaning, farming, and industrial use. It helps in maintaining health and supports agriculture and industries. Without water, life cannot exist on Earth.
  2. Describe the three states of water with examples.
    Answer: Water exists as solid (ice, snow), liquid (rivers, lakes, oceans), and gas (water vapor in the air). These states can change depending on temperature and conditions.
  3. Explain the water cycle in detail.
    Answer: The water cycle includes evaporation (water changes to vapor), condensation (vapor forms clouds), and precipitation (rainfall, snowfall). This cycle maintains the natural availability of water.
  4. What are the causes and effects of water scarcity?
    Answer: Causes include wastage, overpopulation, uneven rainfall, and pollution. Effects are shortage for drinking, farming problems, and decline in groundwater levels.
  5. How can you contribute to saving water at home?
    Answer: By closing taps properly, using water carefully while bathing or washing, recycling water for plants, and encouraging rainwater harvesting at home.
  6. What is groundwater and why is it important?
    Answer: Groundwater is water stored under the earth in aquifers. It is important because it supplies water where rivers and lakes are not available.
  7. Discuss any five methods of water conservation.
    Answer: (1) Rainwater harvesting (2) Reuse of water (3) Planting more trees (4) Fixing leaks (5) Avoiding wastage in daily life.