INTRODUCTION/DEFINITION :
Green plants converts carbon dioxide into glucose in the presence of sunlight.
The atmosphere keeps the average temperature of the earth fairly steady during the day and even during the course of the whole year.
All the movements of air resulting in diverse atmospheric phenomena are causing by the uneven heating of the atmosphere in different regions of the earth.
Rainfall patterns are decided by the prevailing wind patterns.
The fossil fuels like coal and petroleum contain small amounts of nitrogen and sulphur.
Most of the water on earth’s surface is found in seas and oceans and is saline.
The outermost layer of our Earth is called the crust and the minerals found in this layer supply a variety of nutrients to life – forms.
Modern farming practices involve the use of large amounts of fertilizers and pesticides.
Use of these substances over long periods of time can destroy the soil structure by killing the soil micro – organisms that recycle nutrients in the soil.
The whole process in which water evaporates and falls on the land as rain and later flows back into the sea via river is known as the water cycle.
There is a nitrogen cycle in nature in which nitrogen passes from its elemental form in the atmosphere into simple molecules in the soil and water.
Carbon dioxide is one of the greenhouse gases.
Oxygen is a very abundant element on our earth. It is found in the elemental form in the atmosphere to the extent of 21%.
Ozone absorbs harmful radiations from the sun.
Atmosphere maintains the average temperature of the earth fairly steady not only during the day but throughout the year.
Winds are basically caused by heating of air in certain parts. The hot air rises upwards. This creates an area of low pressure. Cooler air from adjacent higher pressure areas passes into this area. This creates wind
Clouds are wet air masses that float in the direction of prevailing wind.
Partially decomposed organic matter or humus mixes with weathered rock particles to form soil. Humus helps in formation of soil crumbs which are essential for maintaining proper hydration and aeration of soil.