notes of the chapter natural resources for class 9 biology
Answers
Introduction to Natural Resources
Earth is the only one on which life exists. The resources of the earth are the land, the water and the air. Other resources include fossil fuels, sunlight, wind, minerals etc. Biotic factors referred to as living things in the ecosystem. The air, the water and the soil form the non-living or abiotic component of the biosphere.
Air and Air Pollution
An atmosphere is a layer of gases that surrounds a planet. Atmospheric air has 78% nitrogen, 21%oxygen and, 1% of other gases by volume.
Role of atmosphere
The atmosphere keeps the average temperature of earth steady. It slows down the escape of heat into outer space during the night and prevents a sudden increase in temperature during the day.
Air pollution
Air pollution is caused by the introduction of pollutants, organic molecules, or other unsafe materials into Earth’s atmosphere
Causes: Man-made sources include combustion of fuel, smoke from industries, Burning crackers etc. Natural sources include forest fires, volcanoes etc.
Effects: Respiratory diseases, Global warming, Acid Rain etc.
no I don't have my notes.
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