A Journey through States of Water

(c)

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(b)

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(a)

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(c)

(b)

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(c)

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(b)

(d)

(a)

(d)

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states

evaporation

condensation

invisible

humidity

retains

container

melting

freezing

faster

hot sunny

evaporate

water cycle

rain

clouds

False

True

False

True

True

False

True

False

False

True

True

False

True

True

False

A–5, B–3, C–2, D–1, E–4

A–3, B–5, C–1, D–2, E–4

(c)

(a)

(c)

(a)

(b)

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(b)

(b)

Hint: Ice (solid) and water (liquid); water vapour is the third state introduced later.

Hint: Conversion of water into its vapour state; e.g., drying of wet clothes, mopped floor, sweat, or water disappearing from a steel plate.

Hint: Water vapour itself is invisible, but the presence of tiny droplets of water in steam makes it visible.

Hint: Conversion of water vapour into liquid state; e.g., water droplets on the outer surface of a cold glass tumbler, dew drops.

Hint: Water vapour in the air comes in contact with the cold surface and condenses into water droplets.

Hint: The amount of water vapour present in the air.

Hint: Retains its shape irrespective of the container; does not flow or spread.

Hint: Spreads out in the entire available space; does not possess a fixed shape.

Hint: No — water takes the shape of the container but its volume remains constant.

Hint: Melting — conversion of a solid into a liquid state; Freezing — conversion of a liquid into a solid state.

Hint: By supplying heat to it.

Hint: Wax, oil, ghee (also coconut oil).

Hint: Heat from the sun makes water in the clothes evaporate faster.

Hint: Increased movement of air makes water evaporate faster (clothes dry faster on a windy day).

Hint: Water seeps through the surface of the pot and evaporates, which imparts a cooling effect.

Hint: Sprinkling water on the floor/roof in summer; feeling cool when sweat evaporates under a fan; cool sensation from rubbing sanitiser.

Hint: A clay pot (surahi) used to keep water cold in summers.

Hint: Water vapour is lighter than air, so it rises.

Hint: The circulation of water between the Earth's surface and the atmosphere — water evaporates, forms clouds, returns as rain/hail/snow and flows back to oceans.

Hint: Most water is in oceans and cannot be used directly; increasing population causes shortage, so we must avoid wasting it and keep water bodies pollution-free.

Introduction: Ice and water are two forms or states of the same substance — water — but they behave differently.
Key Points:
1. Same substance — Ice and water are the two states of the same substance; ice is the solid state and water is the liquid state.
2. Difference in flow — Water flows but ice does not; water splashes but ice does not.
3. Difference in feel — Ice feels hard and can be held in the hands, whereas water cannot be held in the same way.
Conclusion: Though ice and water are the same substance, their different states give them different physical behaviours.

Introduction: An activity with a steel plate demonstrates that water does not seep through but disappears by changing state.
Key Points:
1. Activity setup — A tablespoon of water was placed on a steel plate and observed at regular intervals.
2. Observation — The water did not seep through to the other side of the plate but disappeared after some time.
3. Explanation — The water converted into its gaseous state called water vapour through the process of evaporation.
Conclusion: Water on a steel plate disappears not by seeping through but by converting into water vapour through evaporation.

Introduction: Water droplets appear on the outer surface of a glass tumbler containing cold water due to condensation.
Key Points:
1. Setup — Cold water with ice cubes was taken in a glass tumbler and left undisturbed for five minutes.
2. Observation — Water droplets appeared on the outer surface of the glass tumbler and combined to form bigger drops.
3. Reason — Water vapour in the air came in contact with the cold surface of the tumbler and condensed into water droplets.
Conclusion: The water droplets on the outside of the tumbler are formed by condensation of water vapour from the air.

Introduction: Activity 8.4 uses a digital weighing balance to investigate whether water seeps through the glass tumbler.
Key Points:
1. Setup — A glass tumbler half-filled with water and ice was covered with a steel plate and weighed on a digital weighing balance.
2. Mass increases — The mass was found to increase over time as condensed water collected on the outer surface.
3. Water level constant — Marking the water level showed it did not go down, proving water was not seeping and the outside water came from condensation.
Conclusion: The increasing mass and constant water level prove that water does not seep through the glass tumbler; the droplets come from condensation.

Introduction: Water exists in three states — solid (ice), liquid (water) and gas (water vapour) — which differ in their properties.
Key Points:
1. Ice (solid) — Ice retains its shape regardless of the container and does not flow or spread.
2. Water (liquid) — Water takes the shape of the container, flows and spreads while keeping its volume constant.
3. Water vapour (gas) — Water vapour has no fixed shape and spreads out in the entire available space.
Conclusion: The three states of water differ in shape, flow and spreading behaviour, reflecting their distinct physical properties.

Introduction: Activity 8.7 investigates how the exposed area of water affects the rate of evaporation.
Key Points:
1. Setup — Equal amounts of water were taken in a bottle cap (small exposed area) and on a plate (large exposed area).
2. Observation — The time taken for complete evaporation was recorded for both, and the plate's water evaporated faster.
3. Conclusion — A larger exposed area leads to faster evaporation because more water is exposed to air.
Conclusion: The activity shows that increasing the exposed area of water increases the rate of evaporation.

Introduction: Sunlight and wind are two factors that significantly affect how fast water evaporates.
Key Points:
1. Sunlight effect — Water kept in sunlight evaporates faster than water kept in shade.
2. Wind effect — Clothes dry faster on a windy day due to increased air movement, which speeds up evaporation.
3. Combined example — Clothes dry fastest on a hot, sunny and windy day, showing both sunlight and wind increase evaporation.
Conclusion: Both sunlight and wind increase the rate of evaporation, as observed in everyday examples like drying clothes.

Introduction: A pot-in-pot cooler is a simple, electricity-free device that uses evaporation to create a cooling effect.
Key Points:
1. Structure — Two earthen pots of different sizes are used; the smaller pot is placed inside the larger one with sand filled in the gap between them.
2. Water in sand — Water is poured into the sand and a wet jute sack or lid covers the top of the smaller pot.
3. Cooling mechanism — Evaporation of water from the sand and pots creates a cooling effect that keeps vegetables and fruits fresh inside.
Conclusion: The pot-in-pot cooler uses the principle of evaporation to create a cooling effect without electricity.

Introduction: Activity 8.10 demonstrates that dust particles play an essential role in the formation of clouds.
Key Points:
1. Initial setup — A plastic bottle with water was squeezed and released; little happened without dust particles.
2. Adding burnt paper — A small burnt piece of newspaper was added to provide invisible dust particles.
3. Cloud formation — Squeezing and releasing now produced haziness (clouds) above the water, as water vapour condensed around the dust particles.
Conclusion: Dust particles are essential for cloud formation, as water vapour condenses around them to form clouds.

Introduction: Clouds are formed when water vapour rises and condenses, and they give us rain when droplets become heavy.
Key Points:
1. Rising air — Air rises and becomes cooler; water vapour, being lighter than air, also rises.
2. Cloud formation — At heights, the vapour cools and condenses into tiny droplets around dust particles, forming clouds.
3. Rainfall — Many droplets join to form bigger drops; when these drops become heavy, they fall as rain, sometimes as hail or snow.
Conclusion: Clouds form from condensed water vapour and produce rain when the droplets grow heavy enough to fall.

Introduction: The water cycle is the continuous circulation of water between the Earth's surface and the atmosphere.
Key Points:
1. Evaporation — Water from oceans and the Earth's surface evaporates into the atmosphere as water vapour.
2. Return as precipitation — The vapour returns to the Earth as rain, hail or snow.
3. Flow back to oceans — The water ultimately flows back to the oceans, completing the continuous circulation called the water cycle.
Conclusion: The water cycle describes the continuous movement of water through evaporation, condensation, precipitation and flow back to oceans.

Introduction: Only a small portion of the Earth's water is fit for use, making conservation essential.
Key Points:
1. Most water in oceans — Most of the water on Earth is in the oceans and cannot be used directly for drinking or daily use.
2. Increasing demand — The increasing population raises the demand for water, causing shortage in many parts of the world.
3. Need for conservation — We must use water wisely, avoid wasting it and keep water bodies free from pollution.
Conclusion: Since only a small portion of water is fit for use and demand is rising, conserving water is essential.

Introduction: The rate of evaporation of water is affected by several environmental conditions.
Key Points:
1. Exposed area — A larger exposed area leads to faster evaporation, as seen with water on a plate versus a bottle cap.
2. Temperature and sunlight — Higher temperature and sunlight increase the rate of evaporation, as water evaporates faster in sunlight than in shade.
3. Wind and humidity — Wind increases evaporation, while higher humidity (more water vapour in air) slows it down.
Conclusion: Exposed area, temperature/sunlight, and wind/humidity are key conditions that affect the rate of evaporation.

Introduction: Evaporation produces a cooling effect, which is observed in several everyday situations.
Key Points:
1. Matka (earthen pot) — Water seeps through the surface of a matka and evaporates, imparting a cooling effect that keeps the stored water cool.
2. Sprinkling water on roof/floor — Sprinkling water on a roof or floor during summer cools it as the water evaporates.
3. Sweat under a fan — Sitting under a fan cools us because the wind helps sweat to evaporate from our body.
Conclusion: Evaporation causes cooling, as demonstrated by a matka cooling water and sprinkling water cooling surfaces in summer.

Introduction: Water changes its state when heated or cooled, and each change is named as a specific process.
Key Points:
1. Heating — melting — On heating, ice (solid) melts and converts into water (liquid); this process is called melting.
2. Heating — evaporation — On further heating, water (liquid) converts into water vapour (gas); this process is called evaporation.
3. Cooling — freezing and condensation — On cooling, water freezes into ice (freezing), and water vapour condenses into water (condensation).
Conclusion: Heating causes melting and evaporation, while cooling causes freezing and condensation, changing the states of water.

Hint: (a) It could have seeped into the ground, evaporated, or both; (b) Place a tablespoon of water on a steel plate and observe whether water seeps to the other side; (c) Water converts into the gaseous state called water vapour — the process is evaporation.

Hint: (a) From water vapour present in the air; (b) No — the water level inside does not go down (as shown by marking it); (c) Condensation — the conversion of water vapour into its liquid state on contact with a cold surface.

Hint: (a) The mass increased — water vapour from the air condenses on the cold tumbler, adding water droplets outside; (b) Mark the water level inside with a marker/tape — the level does not go down, showing water is not seeping out and the outer water is only from condensation.

Hint: (a) The amount of water and the surroundings; (b) The exposed area of water (cap vs plate); (c) Larger exposed area makes evaporation faster; other conditions include temperature/sunlight, wind, or humidity.

Hint: (a) The cap in sunlight; (b) Heat/sunlight makes water evaporate faster; (c) On a windy day evaporation is even faster due to air movement; on a rainy day it is slower because the air already has more water vapour (humidity).

Hint: (a) Water seeps through the surface of the earthen pot and evaporates, causing a cooling effect; stainless steel does not allow seeping; (b) Sprinkling water on the floor/roof in summer; (c) The wind helps the sweat on our body to evaporate, which cools us.

Hint: (a) Water vapour is lighter than air; (b) Around dust particles; (c) The droplets form clouds; many droplets join to form bigger drops which become heavy and fall as rain (sometimes hail or snow).

Hint: (a) Place the smaller pot in the centre of the larger one, fill the gap with sand, pour water in the sand, cover the top with a lid or wet jute sack; (b) Water evaporates from the sand and pots, causing cooling; (c) Surahi.

Hint: (a) Ice (solid); (b) Water (liquid); (c) Ice retains its shape and does not spread; water takes the container's shape, flows and spreads with constant volume; water vapour has no fixed shape and spreads through the entire available space.

Hint: (a) Evaporation; (b) Evaporation takes place continuously, even at room temperature; (c) Sprinkle a little water on the seat — as it evaporates it will cool the seat (cooling effect of evaporation).

Introduction: Evaporation is the process by which water converts into its gaseous state called water vapour.
Key Points:
1. Definition — The process of conversion of water into its vapour state is called evaporation.
2. Examples of disappearance — Water disappears from wet clothes, mopped floors, sweat on our body, puddles and a steel plate through evaporation.
3. Hot pan example — Water sprinkled on a hot pan disappears as it converts into steam, which is water vapour.
4. Hand sanitiser — Hand sanitiser disappears as we rub it on our hands, another example of evaporation.
5. Occurs at room temperature — Evaporation takes place continuously, even at room temperature, as seen from drying of clothes and floors.
Conclusion: Evaporation is the continuous conversion of water into vapour, occurring at all temperatures including room temperature, as seen in many daily examples.

Introduction: Condensation is the process by which water vapour converts into its liquid state, as seen on cold surfaces.
Key Points:
1. Definition — The process of conversion of water vapour into its liquid state is called condensation.
2. Activity observation — Cold water with ice cubes in a glass tumbler produced water droplets on its outer surface, which combined to form bigger drops.
3. Weighing balance evidence — Covering the tumbler with a steel plate and weighing it showed the mass increased as condensed water collected outside.
4. Water level evidence — Marking the water level showed it did not go down, proving water was not seeping through the glass.
5. Conclusion from activity — The outside water came from condensation of water vapour in the air, not from seeping through the glass.
Conclusion: Condensation causes water droplets on cold surfaces, and the weighing and water level evidence proves water does not seep through glass.

Introduction: Water exists in three states — solid, liquid and gas — each with distinct properties.
Key Points:
1. Solid (ice) — shape — Ice retains its shape irrespective of the container in which it is placed.
2. Solid (ice) — flow and spread — Ice does not flow and does not spread; it remains in its fixed shape.
3. Liquid (water) — shape, flow and spread — Water takes the shape of the container, flows and spreads while keeping its volume constant.
4. Gas (water vapour) — shape and spread — Water vapour has no fixed shape and spreads out in the entire available space.
5. Gas (water vapour) — visibility — Water vapour exists even at room temperature but is invisible to us; it is present in the air around us.
Conclusion: The three states of water differ in shape, flow, spreading and volume, reflecting their distinct physical characteristics.

Introduction: Melting and freezing are two processes by which substances change between solid and liquid states.
Key Points:
1. Melting — The process of conversion of a solid into liquid state is called melting; for example, ice melts into water and candle wax melts into liquid on heating.
2. Freezing — The process of conversion of liquid into solid state is called freezing; for example, water freezes into ice in a freezer.
3. Other substances — Coconut oil solidifies in winter (freezing) and liquefies when warmed (melting); liquid wax cools back into solid wax.
4. Effect of heating — Heating changes ice to water (melting) and water to water vapour (evaporation), moving from solid to liquid to gas.
5. Effect of cooling — Cooling changes water to ice (freezing) and water vapour to water (condensation), moving from gas to liquid to solid.
Conclusion: Melting and freezing are reverse processes that change states on heating and cooling, applicable to water and many other substances.

Introduction: The rate of evaporation of water is influenced by several conditions that can be investigated through activities.
Key Points:
1. Exposed area — A larger exposed area causes faster evaporation; water on a plate evaporates faster than in a bottle cap.
2. Temperature and sunlight — Water evaporates faster in sunlight than in shade, as demonstrated by keeping water caps in sunlight and shade.
3. Wind and air movement — Clothes dry faster on a windy day due to increased air movement, which speeds up evaporation.
4. Humidity — On a rainy or humid day, water evaporates slowly because the air already holds more water vapour.
5. Combined example — Clothes dry fastest on a hot, sunny and windy day, and slowest on a rainy day, showing all conditions together.
Conclusion: Exposed area, temperature, wind and humidity are the key conditions that determine how fast or slow water evaporates.

Introduction: Evaporation produces a cooling effect, which is utilised in several everyday devices and practices.
Key Points:
1. Matka (earthen pot) — Water seeps through the surface of a matka and evaporates, imparting a cooling effect that keeps the stored drinking water cool.
2. Pot-in-pot cooler — Two earthen pots with sand and water between them create a cooling effect by evaporation, keeping vegetables and fruits fresh without electricity.
3. Sprinkling water on roof/floor — Sprinkling water on a roof or floor during summer cools the surface as the water evaporates.
4. Sweat under a fan — Sitting under a fan cools us because the wind helps sweat evaporate from our body, removing heat.
5. Sanitiser cooling — Rubbing hand sanitiser on the hands feels cool because the sanitiser evaporates quickly, absorbing heat.
Conclusion: Evaporation causes cooling, as demonstrated by a matka, a pot-in-pot cooler, sprinkling water, sweat evaporation and sanitiser.

Introduction: Clouds are formed by the condensation of water vapour in the atmosphere and give us rain, hail or snow.
Key Points:
1. Rising air and vapour — Air rises and becomes cooler; water vapour, being lighter than air, also rises into the atmosphere.
2. Condensation and clouds — At heights, the vapour cools and condenses into tiny droplets around dust particles, forming clouds.
3. Role of dust particles — Dust particles are essential for condensation; water vapour condenses around them, as shown in Activity 8.10 with burnt newspaper.
4. Formation of bigger drops — Many tiny droplets join together to form bigger drops of water in the clouds.
5. Rain, hail or snow — When drops become heavy, they fall as rain; under special conditions, they may fall as hail or snow.
Conclusion: Clouds form when water vapour condenses around dust particles at heights, and they produce rain, hail or snow when the drops become heavy.

Introduction: The water cycle is the continuous circulation of water between the Earth and the atmosphere, and conservation is essential due to limited usable water.
Key Points:
1. Evaporation — Water from oceans and the Earth's surface evaporates into the atmosphere as water vapour.
2. Precipitation — The vapour returns to Earth as rain, hail or snow through condensation and cloud formation.
3. Flow back to oceans — The water ultimately flows back to the oceans, completing the continuous circulation called the water cycle.
4. Limited usable water — Only a small portion of water available on Earth is fit for use; most water is in oceans and cannot be used directly.
5. Need for conservation — The increasing population raises demand and causes water shortage, so we must use water wisely, avoid waste and keep water bodies pollution-free.
Conclusion: The water cycle ensures continuous circulation of water, but since only a small portion is fit for use, conservation is crucial.

Introduction: An activity with a steel plate investigates whether water seeps through it or disappears by another process.
Key Points:
1. Activity setup — A tablespoon of water was placed on a steel plate and observed at regular intervals.
2. Observation — The water did not seep through to the other side of the steel plate but disappeared after some time.
3. Hot pan example — Similarly, water sprinkled on a hot pan disappears into steam, confirming water does not seep through metal surfaces.
4. Conclusion about disappearance — The water converted into water vapour through the process of evaporation, not by seeping through.
5. State change — The investigation shows that water does not seep through steel or glass but changes its state from liquid to gas.
Conclusion: Water does not seep through a steel plate but disappears by converting into water vapour through evaporation, demonstrating a change of state.

Introduction: Evaporation is a key process in daily life that helps in drying, cooling and the water cycle.
Key Points:
1. Drying clothes — Wet clothes dry because water evaporates from them into the air.
2. Drying mopped floors — Water left on floors after mopping disappears through evaporation.
3. Sweat evaporation — Sweat on our body evaporates, cooling us down, especially under a fan.
4. Drying of puddles and sanitiser — Water in puddles evaporates, and hand sanitiser disappears as it is rubbed on the hands.
5. Cooling and water cycle — Evaporation cools water in a matka and cools surfaces when sprinkled; it is also a key process in the water cycle.
Conclusion: Understanding evaporation helps us dry clothes faster (on a sunny, windy day, spread out), keep things cool and appreciate the water cycle's role in nature.
NCERT "Curiosity" (2024 edition, Reprint 2026-27) — Chapters 9–12
For: Class 6 exam preparation | Syllabus covered:
- Chapter 9: Methods of Separation in Everyday Life
- Chapter 10: Living Creatures: Exploring their Characteristics
- Chapter 11: Nature's Treasures
- Chapter 12: Beyond Earth
Question pattern per chapter (150 questions): Section A – 55 MCQs (1 mark) | Section B – 15 Fill in the Blanks | Section C – 15 True/False | Section D – 2 Match the Columns (5 pairs each) | Section E – 8 Assertion-Reason (1 mark) | Section F – 20 Short Answer (2 marks) | Section G – 15 Short Answer (3 marks) | Section H – 10 Case/Source-Based (4 marks) | Section I – 10 Long Answer (5 marks)