The Atmosphere

- The earth is surrounded by a thin layer of air which contains life supporting gases such as oxygen, nitrogen, carbon dioxide, dust particles and water vapor. This layer is called the atmosphere.
- Atmosphere is derived from the Greek words atmos meaning vapor and sphaira meaning sphere.
- It is held in place by the Earth's gravitational force.
- The atmosphere extends up to a height of 1600 km above the mean sea level.
- The thickness of the atmosphere is unknown.
- It acts as a buffer between the Sun and the Earth.
Composition of Air
- The atmosphere is a mixture of many gases, comprising Nitrogen (78%), Oxygen (21%), Argon (0.93%), Carbon Dioxide (0.03%) and 0.04% of other gases such as neon, helium, krypton, xenon, hydrogen and ozone.
- A considerable amount of water vapor is found in the atmosphere through evaporation of water from the oceans, lakes and rivers.
- It also contains soot, salt, dust, dirt, plant pollen and bacteria.
- The upper atmosphere mainly comprise helium and hydrogen as they are light gases.


Leave a Reply

Your email address will not be published. Required fields are marked *