Explanation:

1. NITROGEN AND OXYGEN ARE THE TWO MAJOR CONSTITUENTS OF AIR. NITROGEN FORMS ABOUT 78 PERCENT AND OXYGEN FORMS ABOUT 21 PERCENT OF DRY AIR BY VOLUME. AIR ALSO CONTAINS CARBON DIOXIDE WHICH FORMS ABOUT 0.03 PERCENT OF THE VOLUME OF AIR. THE REMAINING PART OF AIR CONSISTS OF INERT GASES ,WATER VAPOUR AND DUST.

2. The experiment is supposed to show that air has weight. You first make a balance by tying a piece of string around the center point of the yardstick and then tying the other end of the string to something LIKE a shower rod, so that the yardstick balances. This may take some work, so be patient.

3. The atmosphere protects living things from the Sun's most HARMFUL rays. Gases reflect or absorb the strongest rays of sunlight (Figure below). Theatmosphere SHIELDS Earth from the most harmful solar rays.

4. Earth's Atmospheric Layers

Troposphere. The troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). ...Stratosphere. The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high. ...Mesosphere. ...Thermosphere. ...Ionosphere. ...Exosphere. ...Credit: NASA/Goddard.

5.

The main properties of water are its polarity, COHESION, adhesion, surface tension, high specific heat, and evaporative cooling. A water molecule is slightly charged on both ends. This is because oxygen is more electronegative than hydrogen.Aug 22, 2014

6. Sedimentation can be defined as the settling down of suspended, insoluble, heavy solid particle in a solid-liquid mixture. (b) Decantation can be defined as the process of pouring out the clear liquid without disturbing the sediment.