Transcript Learning Objectives

How to get pure water from
dirty water
The water from ponds or rivers often looks quite dirty.
It contains many impurities that are dissolved in the
water. It also contains bacteria.
Boiling the water in a kettle kills the bacteria, but it
does not remove all of the impurities.
When the kettle boils, the water turns into water
vapour. This is invisible!
The impurities are left behind in the kettle.
As the water vapour cools, it condenses back into tiny
droplets of water that form clouds of steam.
The water vapour cools faster on cool surfaces such as
mirrors or windows. We call it condensation.
Here, condensation is forming on a flask full of iced
water. It is dripping down into a glass.
The water that collects is pure distilled water. It is safe
to drink.