Which gas present in the atmosphere helps plants to prepare their food?
Nitrogen
Hydrogen
Carbon dioxide
Oxygen
The layer of the atmosphere in which we live is the :
Troposphere
Stratosphere
Mesosphere
Thermosphere
What is atmosphere?
Mixture of gases that surrounds the earth
Mixture of gases that surrounds the sun
Mixture of gases that surrounds the moon
Mixture of gases that surrounds the planets
What percentage of the atmosphere consists of nitrogen?
68
76
78
88
How long should water be boiled to kill germs?
3 minutes
5 minutes
8 minutes
10 minutes
Which is the uppermost layer of the atmosphere?
Exosphere
The process by which the impurities in the water gets settle down is called:
Sedimentation
Decantation
Distillation
Filtration
What do we need to breathe?
Inhaler
Smell
Vaporizer
Air
Which is the first layer of the atmosphere?
Air is a mixture of many:
Gases
Germs
Dust
Vapour
