1. Mixture of gases is termed air
   1. Nitrogen(78%)
   2. Oxygen(21%)
   3. Argon(0.93%)
   4. Carbon Dioxide(0.03%)
   5. Water Vapour
   6. Other Gases
2. Atmosphere
   1. Troposphere
   2. Stratosphere
   3. Mesosphere
   4. Ionosphere
   5. Thermosphere
   6. Exosphere
3. Wind
   1. Horizontaly moving air
4. Air pressure
   1. Air has weight and hence exerts pressure
5. Periodic Winds
   1. Winds which blow periodically from different directions
      1. Land and Sea Breeze
      2. Valley and Mountain Winds
      3. Monsoon Winds
6. Wind Vane
   1. A device that measures Wind direction
7. Cyclone
   1. Low pressure area with winds blowing anti-clockwise in North Hemisphere
8. Humidity
   1. Amount of water vapour in air
      1. Saturated Air
         1. Air that reaches dew-point
      2. Unsaturated Air
         1. Air that didn't reach dew-point