• All living organisms on the Earth need air to survive.
  • A thick blanket of air, called the atmosphere, surrounds our Earth.
  • The Earth’s atmosphere has a portion that contains high levels of ozone gas.
  • This layer, called the ozone layer, protects us from the harmful ultraviolet rays of the sun, thus preventing many eye problems and skin cancer in human beings.
  • Air cannot be seen but it can be felt when it moves.
  • Air, when moves, help light-weight things move. For example, the leaves of the trees rustling or clothes on the clothesline swaying.
  • Moving air is called wind.
  • Moving air helps us in many ways. For example, wind helps paper boat, aeroplane, and pinwheel move.
  • It also helps big ships, sailboats, windmills, and hot-air balloons move.
  • Air is present all around us.
  • Air is also present in things which seem to be empty.