Air and Water

Essential for Life - Air & Water Worksheet-6

12. True/False

a.      Troposphere is the lowest layer of the earth.

b.      Thermosphere is the fourth layer (from the top) of the earth.

c.      We can get clean water by filtering the muddy water through cotton balls.

d.      Evaporating seawater is the oldest method of obtaining salt.

e.      Boiled water should be stored in a clean covered container.

f.       Pebbles are soluble in water.

Essential for Life - Air & Water Worksheet-8

11. True/False

a.      Air contains only oxygen.

b.      Exosphere is the middle layer of the earth.

c.      Atmosphere can be divided into five layers.

d.      Filtration and sedimentation methods are used to separate soluble impurities.

e.      Germs present in the water can make us ill.

f.       Boiled water is the purest form of water that is used in laboratories.

Essential for Life - Air & Water Worksheet-9

Multiple-Choice Question:

1. What percentage (%) of nitrogen is present in the air?

(A) 78%                        (B) 75%                        (C) 79%

2. Which of the following gas is responsible for depletion of ozone layer?

(A) Methane               (B) Propane                (C) Chlorofluorocarbons