Ms. Mahnaz Mujtaba

Grade V

DA PUBLIC SCHOOL O & A LEVELS

WATER

Sources of waterImpurities present in waterMethods to remove insoluble impuritiesRemoval of germsTown water supply

SOURCES

Oceans Rivers Ponds Lakes Rain Wells; The under ground water

Properties of drinking water

It must be clean & clear. It should be free from germs. Good in taste. Contain important minerals like calcium,

iodine, potasium,and iron.

IMPURITIES

Insoluble impurities

Soluble impurities

INSOLUBLE IMPURITIES

Things that do not dissolve in water

Examples:

Mud, Sand, Chalk, Pebbles, Stones, Paper

ETC.

Methods to remove Insoluble Impurities

Sedimentation & Decantation:

Sedimentation is a process in which insoluble impurities are settle down at the bottom to form sediments.

Decantation :

It is the pouring off the clear water from the top into another vessel leaving the sediments behind.

Filtration

It is a process in which insoluble material is separated from water by using filter paper or filter bed.

Sieving

Insoluble material is removed by using different kinds of sieves.

Example;

Tea leaves can be separated from tea with the help of sieves.

Methods to remove germs from water

Chlorination:

Small amount of chlorine is added to kill germs. Boiling:

Boil water for at least 15 minutes to kill germs. Water purifiers:

Water purifiers are used to kill germs by ultra violet light.

Town water supply

Water supplied to our homes is treated in three steps to purify it;

Sedimentation & Decantation: Filtration: Chlorination

Conclusion

Water is a bounty of Allah.

71% of our body is water.

Drink at least 8 glasses of water to stay healthy.

Do not waste water. Our Prophet (s.a.w) also forbid to waste water.

Resources:

Awareness science book V Science directions level V Science world by machlay