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📚 Class VI Science 📘 NCERT Solutions Ch 8 - A Journey through States of Water

Class VI NCERT solutions A Journey through States of Water

Class VI Science • Curiosity

💧 Chapter 8: A Journey through States of Water

NCERT Solutions — Complete Question & Answer Guide

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📌 Key Concepts

✦ Water exists in 3 states: Solid (ice), Liquid (water), Gas (water vapour)

✦ Melting: Ice→Water (0°C); Freezing: Water→Ice (0°C)

✦ Evaporation: Water→Vapour (any temp, from surface)

✦ Boiling: Water→Steam (100°C, throughout liquid)

✦ Condensation: Vapour→Water (cooling)

✦ Evaporation causes cooling (sweating, earthen pot)

✦ Factors: temperature, surface area, wind speed, humidity

✦ Water Cycle: Evaporation→Condensation→Precipitation→Collection

📝 Let Us Enhance Our Learning

Q1 Fill in the blanks.
ANSWER
StatementAnswer
Conversion of water to vapour is ______.evaporation
Conversion of vapour to water is ______.condensation
Water changing to ice is ______.freezing
Ice melts at ______.0°C
Water boils at ______.100°C
Q2 True or False.
ANSWER

(i) Evaporation occurs only at boiling point. FALSE
Evaporation occurs at all temperatures.

(ii) Temperature remains constant during change of state. TRUE

(iii) Boiling and evaporation are same. FALSE
Boiling: at 100°C, throughout liquid. Evaporation: any temp, only from surface.

(iv) Water vapour is present in air. TRUE

Q3 How does evaporation cause cooling?
ANSWER

During evaporation, water molecules absorb heat from surroundings to change to vapour. This makes the surface cooler.

  • Feeling cold after bath (water evaporates from skin)
  • Earthen pot (matka) keeps water cool
  • Sweating cools our body
Q4 Factors affecting rate of evaporation?
ANSWER
FactorEffect
TemperatureHigher → faster
Surface areaLarger → faster
Wind speedMore wind → faster
HumidityLess humidity → faster
Q5 Difference between evaporation and boiling.
ANSWER
FeatureEvaporationBoiling
TemperatureAny temperatureOnly at 100°C
WhereSurface onlyEntire liquid
SpeedSlowFast, with bubbles
CoolingYesNo
Q6 Explain the water cycle.
ANSWER
  1. Evaporation: Sun heats water → vapour rises
  2. Condensation: Vapour cools at height → forms clouds
  3. Precipitation: Clouds heavy → rain/snow/hail falls
  4. Collection: Water collects in rivers, oceans, underground → cycle repeats
Q7 Why does ice temperature stay 0°C while melting?
ANSWER

The heat supplied is used to break bonds between ice molecules (latent heat of fusion), not to raise temperature. So temperature stays at 0°C until all ice melts.

Q8 Why do droplets appear on a cold glass?
ANSWER

Water vapour in air contacts the cold surface → condenses into tiny droplets. Same principle as dew formation.

Q9 Why do clothes dry faster on a windy day?
ANSWER

Wind carries away water vapour from clothes, keeping nearby air dry → increases rate of evaporation.

Q10 Why spread clothes for drying instead of folding?
ANSWER

Spreading increases surface area exposed to air → evaporation is faster → clothes dry faster.

UNIQUE STUDY POINT BY SUMEET SAHU

Amitesh Nagar, Indore, Madhya Pradesh | uniquestudyonline.com

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