Page 69 - Science class 4

Bigger water droplets fall as rain. On cold winter mornings, we see droplets of

water on the grass and on green leaves. These are called dewdrops . These
droplets are also formed by the condensation of water vapour.

Condensing water Cloud formation
Condensing water
Condensing water
Cloud formation
Cloud formation
vapour
vapour
vapour
Precipitation
Rain

Surface
Surface
Snow Surface
Runoff
Runoff
Runoff

Groundwater
Groundwater
Evaporation -
Evaporation - Groundwater
Evaporation -
Ocean contributes
Ocean contributes
Ocean contributes
about 80% of total
about 80% of total
about 80% of total
water vapour in air.
water vapour in air.
water vapour in air.
Ocean
Ocean
Ocean

Water-cycle
Water-cycle
Water-cycle
In nature, the process of evaporation and condensation take place

continuously. Water evaporates from lakes, rivers, oceans and other water
bodies. It condenses and falls as rain, snow etc. This forms the water-cycle.
PURIFICATION OF WATER
PURIFICATION OF WATER OF WATER
PURIFICATION
We should drink only pure and clean water. Impure water can make us sick.

Water from taps can be dirty and impure. Thus, water used for drinking and
cooking needs to be purified. This can be done in the following ways.