Page 150 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

7. Why does water in the clouds come down as snowfall?

Ans. Water in the clouds comes down as snowfall when the temperature in the atmosphere
is below freezing, causing the water droplets or ice crystals in the clouds to form

snowflakes.
G. Long-answer questions

1. Explain water cycle with a diagram.
Ans. The water cycle is a continuous process through which water circulates between the

Earth's oceans, atmosphere and land.
A simplified description of the cycle is given below :

Evaporation: Water from oceans, rivers,
lakes and other bodies of water turns

into water vapour due to heat from the
sun.

Condensation: Water vapour rises into
the atmosphere, cools and condenses

into tiny droplets, forming clouds.
Precipitation: The droplets in the clouds

combine to form larger droplets, which
fall back to Earth as rain, snow, sleet or

hail.

Collection: Water collects in oceans, rivers, lakes and groundwater sources.
Infiltration: Some of the water seeps into the ground, replenishing groundwater

reserves.
Runoff: Water flows over the surface back to larger bodies of water, completing the

cycle.

2. How can you observe the three forms of water :
(a) in nature? (b) at home?

Ans. (a) In nature:

Solid: Snow and ice in glaciers or at higher altitudes.
Liquid: Rivers, lakes and oceans.

Gas: Water vapour in the air, visible as mist or clouds.

(b) At home:
Solid: Ice cubes in the freezer.

Liquid: Water in the tap, drinking water or in the kitchen sinks.
Gas: Steam from boiling water or humid air in a bathroom after a hot shower.

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