👉The earth is surrounded by a layer of gas called the atmosphere.
👉 It provides us with the air we breathe and protects us from the harmful effects of the sun’s rays.
👉 The atmosphere extends up to a height of about 1,600 kilometers.
👉 The atmosphere is divided into five layers.
👉 These layers starting from the earth’s surface are called the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere.
👉 The atmosphere is composed of nitrogen 78 per cent, oxygen 21 per cent and other gases like carbon dioxide, argon and others comprise 1 per cent by volume.
👉 Oxygen is the breath of life and nitrogen helps in the growth of living organisms while carbon dioxide is important as it absorbs heat radiated by the earth, thereby keeping the planet warm.
👉 The density of the atmosphere is maximum at the sea level and decreases rapidly as we go up.
👉 The atmosphere exerts pressure on the earth.
👉 Air moves from high pressure to low pressure.
👉 Moving air is known as wind.