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States of Water

🎓 Class 6 Science CBSE Theory Ch 8 — A Journey through States of Water ⏱ ~8 min
🌐 Language: [gtranslate]

This MCQ module is based on: States of Water

[myaischool_lt_science_assessment grade_level="class_6" science_domain="chemistry" difficulty="basic"]

Chapter 8 Summary — A Journey through States of Water

Three states
Water exists as a solid (ice), liquid (water), and gas (water vapour).
Particles
Particles are packed tight and regular in solids, close but moving in liquids, and far apart and fast in gases.
Six state changes
Melting, Freezing, Evaporation, Boiling, Condensation, Sublimation.
Evaporation causes cooling
That is why sweating and a matka cool us down.
Water cycle
Evaporation → Condensation → Precipitation → Collection — forever.
Humidity
The amount of water vapour in air, measured by a hygrometer.
AWG
A machine that condenses air-moisture into drinking water.
Save water
Less than 1% of Earth's water is easily drinkable — every drop counts.

Key Terms to Remember

Solid: Fixed shape + fixed volume (ice).
Liquid: Fixed volume, takes container shape (water).
Gas: No fixed shape or volume (vapour).
Melting: Solid → liquid (heat).
Freezing: Liquid → solid (cooling).
Evaporation: Liquid → gas, any temp.
Boiling: Fast evaporation at 100 °C.
Condensation: Gas → liquid.
Sublimation: Solid → gas directly.
Transpiration: Plants release vapour.
Precipitation: Rain, snow, hail.
Humidity: Water vapour in air.
Hygrometer: Measures humidity.
AWG: Makes water from air.
Rainwater harvesting: Storing rain.

NCERT-Style Exercises

Question 1
What are the three states of water? Give one example of each.
Water exists in three states:
  1. Solid — example: ice cube in a glass, or snow on a mountain.
  2. Liquid — example: drinking water, rain, water in a river.
  3. Gas — example: water vapour in air, steam rising from a boiling kettle.
All three are the same substance (water); only the arrangement of particles changes.
Question 2
Fill in the blanks: Evaporation is the process of ________________. Condensation is the process of ________________.
Evaporation is the process of a liquid (like water) slowly changing into a gas (water vapour) at any temperature, from its surface.
Condensation is the process of a gas (water vapour) changing back into a liquid (water) when it is cooled.
Question 3
What is the water cycle? Explain with the help of a simple diagram.
The water cycle is the continuous movement of water between the Earth's surface and the atmosphere. The main steps are:
  1. Evaporation — The Sun heats water in oceans, rivers, lakes. Water rises as vapour. Plants add vapour through transpiration.
  2. Condensation — Higher up, the vapour cools and forms tiny droplets that make clouds.
  3. Precipitation — The clouds drop the water as rain, snow or hail.
  4. Collection — Water flows into rivers and oceans, or seeps underground. The cycle starts again.
Sun Cloud Evaporation Rain Flow to ocean / Groundwater
Fig E.1 — Simple diagram of the water cycle
Question 4
Why does ice float on water?
When water freezes, its particles arrange themselves in a regular pattern with small gaps between them. Because of these gaps, ice takes up more space (larger volume) than the same amount of liquid water. The same weight of ice is spread over a bigger volume, so ice is lighter for its size (less dense) than water — and that is why it floats. This is also why a bottle of water cracks when the water inside freezes: the ice needs more room.
Question 5
State which form of water: (i) Fog / mist is the ____ state. (ii) A cloud is made of ____. (iii) Snow is the ____ state. (iv) Steam is the ____ state.
(i) Fog / mist — tiny liquid water droplets hanging near the ground (mostly liquid state, not gas — the real water vapour is invisible).
(ii) Cloud — tiny liquid water droplets (and sometimes ice crystals) floating high in the sky.
(iii) Snowsolid state (frozen water crystals).
(iv) Steam — the white mist we see is small liquid droplets; the real invisible hot water vapour is in the gas state. In everyday language, steam is usually called the gas state of water.
Question 6
Why does a glass of cold water have tiny droplets on its outside on a warm day?
The warm air around the glass contains water vapour. When this vapour touches the cold surface of the glass, it loses heat, cools down, and condenses into tiny liquid water drops. These drops appear on the outside of the glass. The glass is not leaking — the water came from the air itself. This is the same reason dew forms on leaves at dawn.
Question 7
Describe three ways to save water at home.
  1. Close the tap while brushing teeth, soaping hands, or shaving. This simple habit can save several litres per person per day.
  2. Fix leaks immediately. A single dripping tap wastes many buckets every week. Replace worn washers or call a plumber.
  3. Reuse water wisely. Water used for washing rice or vegetables can water the plants. Collect rainwater from the roof into a clean barrel for gardening and cleaning.
Bonus ideas: use a bucket-bath instead of a long shower; run the washing machine only when full; report leaks in the neighbourhood.
Question 8
What is humidity? How does it affect our daily life?
Humidity is the amount of water vapour present in the air. It is measured with an instrument called a hygrometer.
Effects on daily life:
  • High humidity makes the day feel sticky — sweat does not dry easily so we feel hot and tired. Clothes take much longer to dry. Bread and biscuits can go soggy.
  • Low humidity makes air feel dry — skin becomes rough, lips crack, static electricity is common. Clothes dry very fast.
  • Weather scientists use humidity to predict rain and comfort.
Question 9
Why does evaporation cause cooling?
For a liquid to change into a gas during evaporation, its particles need energy (heat). They take this heat from whatever is around them — your skin, the air, the water in a matka. When heat leaves a surface, that surface gets colder. That is why:
  • Sweat evaporating from skin cools the body after exercise.
  • A wet cloth placed on a fever patient's forehead feels cool.
  • Water stored in earthen pots stays cool — water seeping through the clay evaporates and steals heat from the pot.
Question 10
Design an experiment to show that evaporation is faster on a windy day than on a still day.
Aim: To compare evaporation in still vs moving air.
Materials: Two identical small saucers, a marker, a table fan, same amount of water for both.
Procedure:
  1. Pour 50 mL of water into each saucer. Mark the water level on the outside with a marker.
  2. Place saucer A on a calm corner of the table (no air movement).
  3. Place saucer B in front of a table fan switched on at low speed.
  4. Keep both at the same room temperature for one hour.
  5. After one hour, check the new water levels.
Expected observation: Saucer B (in front of the fan) has lost more water than saucer A. The moving air carried away water vapour faster, speeding up evaporation. Conclusion: Wind / moving air increases the rate of evaporation.
Question 11
How is ice prepared in a refrigerator starting from water?
We fill an ice-tray with water and place it in the freezer of a refrigerator. The freezer keeps the temperature well below 0 °C. At this cold temperature, the heat is removed from the water. Its particles slow down and arrange themselves in a regular pattern with tiny gaps — the water freezes into solid ice. This is the liquid → solid state change, called freezing. When we take the ice out and leave it on the table, it gains heat from the air, melts back into water — showing that the change is reversible.
Question 12
Ayush wondered if he could "create" new water by letting ice melt. Did Ayush actually create water, or just change its state? Explain.
Ayush did not create any new water — he only changed its state. The ice was already water, just in its solid form. When heat from the room reached the ice, its particles gained energy, broke out of their fixed pattern, and started sliding past each other — this is melting, the solid → liquid change.

The amount of water stayed the same (same mass of particles). Only the arrangement of those particles changed. So water was not created or destroyed; it simply put on a new "costume" — from solid ice to liquid water.
Chapter Complete! You now understand how water travels through three states, powers the amazing water cycle, and why every drop must be saved for the future.

← Back to Part 1

Frequently Asked Questions — States of Water — Chapter 8 Exercises

What does the topic 'States of Water — Chapter 8 Exercises' cover in Class 6 Science?

The topic 'States of Water — Chapter 8 Exercises' is part of NCERT Class 6 Science Chapter 8 — A Journey through States of Water. It covers the key ideas of states of water, water cycle, state changes, NCERT exercises, explained through everyday examples, labelled diagrams and hands-on activities from the NCERT Curiosity textbook. Class 6 students learn simple definitions, see why each idea matters in daily life, and try short experiments and observations. The lesson uses easy language, colourful pictures and small questions so that young learners build a strong base for higher classes and for competency-based questions in CBSE school tests.

Why is 'States of Water — Chapter 8 Exercises' important for Class 6 NCERT Science?

'States of Water — Chapter 8 Exercises' is important because it builds the first ideas of science that Class 6 students will use again in Class 7, 8 and beyond. NCERT Chapter 8 — A Journey through States of Water — introduces states of water and connects it to things children already see at home, at school and in nature. Learning this topic helps students ask better questions, understand simple news about science, and score well in CBSE tests that use competency-based questions. The chapter also supports NEP 2020 by encouraging curiosity, observation and learning by doing rather than only reading and memorising.

What are the key ideas students should remember from States of Water — Chapter 8 Exercises?

The key ideas in 'States of Water — Chapter 8 Exercises' for Class 6 Science are: states of water, water cycle, state changes, NCERT exercises. Students should be able to say each term in their own words, give one or two easy examples from daily life, and draw a small labelled diagram where needed. A good way to revise is to make flashcards, write a short note in the science notebook, and solve the NCERT in-text and exercise questions of Chapter 8. Linking every idea to something seen at home or school — in the kitchen, garden, playground or sky — makes these ideas easy to remember for unit tests and the annual CBSE examination.

How is States of Water — Chapter 8 Exercises taught using activities in NCERT Curiosity Class 6?

NCERT Curiosity Class 6 Science teaches 'States of Water — Chapter 8 Exercises' through an inquiry-based approach using Predict–Observe–Explain activities. Students first make a guess, then try a small experiment with safe, easily available materials, and finally explain what happened and why. This matches the NEP 2020 focus on learning by doing. For Chapter 8 — A Journey through States of Water — the textbook has hands-on tasks, labelled pictures and thinking questions built for Bloom's Taxonomy Levels 1 to 6. Teachers use these activities, along with competency-based questions (CBQs) and assertion–reason items, to check real understanding instead of only rote learning.

How should Class 6 students prepare for the Chapter 8 exercises?

To prepare for the Chapter 8 — A Journey through States of Water — exercises in NCERT Class 6 Science, students should first revise the theory in Parts 1–3 and make a short note of definitions and diagrams for states of water, water cycle, state changes, NCERT exercises. Next, try each exercise question on their own before looking at the solution. Pay special attention to MCQs, match-the-following, fill-in-the-blanks, assertion–reason and short-answer items, as these often appear in CBSE competency-based tests. Practising with the NCERT Curiosity textbook, the exemplar questions, and the MyAiSchool practice bank helps Class 6 students score better in unit tests and the annual examination.

How does 'States of Water — Chapter 8 Exercises' connect to other chapters of Class 6 Science?

'States of Water — Chapter 8 Exercises' connects to many other chapters in NCERT Class 6 Science Curiosity. The ideas of states of water come back when students study related topics like diversity in the living world, food, magnets, measurement, materials, temperature, water, separation, habitats, natural resources and the solar system. For example, what students learn here helps them build mental pictures for later chapters and for Class 7 and Class 8 Science. Teachers often ask cross-chapter questions in CBSE exams to check if students can use what they learned in Chapter 8 — A Journey through States of Water — in new situations. This linked approach matches the NEP 2020 and NCF 2023 focus on holistic, competency-based learning.

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