NCERT Curiosity · Class 6 · Science
A Journey through States of Water
Ice melts. Puddles vanish. Cold glasses sweat. Water is always changing form, right in front of us.
Evaporation Condensation Cooling Effect The Water Cycle
Key idea
Ice and Water: Two States, One Substance
Leave an ice cube in a cup, and it turns into water — two forms of the same substance.
Ice · solid

Keeps its own fixed shape. Can be held, doesn't flow or spread.

Water · liquid

Takes the shape of its container. Flows and spreads, but keeps its volume.

Key idea
Evaporation
A puddle on the playground disappears by evening — the water doesn't just vanish.
Evaporation turns liquid water into invisible water vapour — it happens continuously, even at room temperature.
Key idea
Condensation
Droplets appear on a cold glass — but they aren't seeping through the glass.
Condensation turns water vapour in the air back into liquid. Dew on morning grass forms the same way.
Key idea
Three States, One Journey
Ice
Fixed shape, no flow
→
Water
Flows, keeps volume
→
Vapour
Fills all available space
Key idea
Faster or Slower Evaporation

More surface area

A plate dries faster than a bottle cap.

Higher temperature

Sunlight dries faster than shade.

More wind

Clothes dry faster on a windy day.

Higher humidity slows it

The air already holds more vapour.

Key idea
The Cooling Effect of Evaporation
The matka effect

Water seeps through the porous walls of an earthen pot and evaporates, cooling the water inside — steel pots don't do this.

Sweating and fanning

Cools our body as sweat evaporates — sprinkling water on floors or roofs cools the same way.

Key idea
Clouds, Rain, and the Water Cycle
STEP 1
Evaporate
From oceans and rivers
→
STEP 2
Rise
Vapour rises and cools
→
STEP 3
Condense
Into clouds
→
STEP 4
Fall
As rain, hail, or snow
Chapter · key terms to remember
Key Terms

Evaporation

Liquid water turning into vapour.

Condensation

Water vapour turning into liquid.

Melting

Solid turning into liquid.

Chapter · key terms to remember
More Key Terms

Freezing

Liquid turning into solid.

Humidity

The amount of water vapour in the air.

Water vapour

The invisible gas form of water.

Chapter · key terms to remember
More Key Terms

Water cycle

The continuous movement of water between Earth and the sky.

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