All things on the earth are associated with air, water and land.
Air is called atmosphere, water is called Hydrosphere and land is called Lithosphere.
BIOSPHERE: living things and the parts of the lithosphere, hydrosphere and atmosphere which they occupy are together called the biosphere. These spheres have formed on the earth naturally.
Natural resources : Air, water and land are the factors important for sustaining the living world on the earth and for fulfilling their basic needs. They are called natural resources.
The atmosphere is an airy layer surrounding the earth, while the surface is composed of both water and land, i.e., the hydrosphere and lithosphere. Of the two, the hydrosphere occupies a much greater percentage.
Air : Nitrogen, oxygen, carbon dioxide, six inert gases, nitrogen dioxide, sulphur dioxide, water vapour, and dust particles make up the atmosphere around the earth. About 80% of the gases in the air are found in the troposphere, whereas this proportion is just 19% in the stratosphere. Moreover, the proportion of gases in the mesosphere and ionosphere continues to decrease. Gases are absent from the exosphere and beyond. In addition to these gases, air also contains water vapour and dust particles. Air is a mixture of several gases that is the primary constituent of the earth’s atmosphere. As we move higher and higher from the surface, the amount of gases in the air decreases. That is, the air becomes rarer at higher altitudes.
Some uses of gases in air
Nitrogen: It is also useful to produce ammonia and in packaging airtight foodstuffs. Nitrogen helps living things build proteins.
Oxygen – Necessary for respiration in living things and for combustion.
• Carbon dioxide – Plants use it for producing their food. Used in fire
extinguishers.
• Argon – Used in electric bulbs.
• Helium – Used for obtaining low temperature and also for generating lift in airships.
• Neon – Used in decorative lights and for street lighting.
• Krypton – Used in fluorescent tubes.
• Xenon – Used in flash photography.
large scale emission of smoke through different agencies. This smoke directly mixes with the atmosphere, disturbing the balance between the constituents of air. This is called air pollution.
The burning of fuel comes with harmful gases, and so does the incomplete combustion of fuels such as wood and coal, resulting in increasingly polluted air.
The burning of fuel comes with harmful gases, and so does the incomplete combustion of fuels such as wood and coal, resulting in increasing pollution of Air.
Harmful substances released in air through combustion of fuels
Nitrogen dioxide
Carbon dioxide
Carbon monoxide
Sulphur dioxide
Soot
Ozone layer :
– The protective shell There is a layer of ozone (O3) gas in the lower part of the stratosphere. Ozone gas is not directly useful for the survival of living things, yet it is very important for living things to have this layer of ozone at a high altitude around the earth. The ultraviolet rays coming from the sun are very harmful for living things. The ozone gas absorbs these rays. As a result, life on earth is protected.
