10 Chemistry The Atmosphere Notes Punjab Curriculum

The Atmosphere MCQ`s ,Short Questions and Long Questions Free PDF Download Punjab Curriculum

Chemistry Chapter 14 The Atmosphere Complete Notes MCQ`s, Short Questions and Long Questions

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Key Points of Chapter 14 The Atmosphere Notes

Atmosphere is the envelope of different gases around the Earth.
Atmosphere is divided into four regions; troposphere, stratosphere, mesosphere and thermosphere.
Troposphere is just above Earth’s surface and extends upto 12 kilometre.
Stratosphere is next to troposphere and extends upto 50 km. In this region, temperature rises upwards because of presence of ozone layer.
Mesosphere is next to stratosphere and extends up to 85 km.
Thermosphere lies beyond mesosphere.
Natural sources of air pollutants are volcanic eruption and decomposition of organic matter.
Source of air pollutants because of human activities are burning of fossil fuel in combustion engines of automobiles, kilns of industries, open air fires and forest fires.
CO2 forms a layer around Earth, that absorbs the infrared radiations emitted by Earth surface. Thus, heating up the atmosphere is called greenhouse effect.
CO is highly poisonous gas so it is health hazard.
SO2 is also health hazard and forms sulphuric acid by combining with water vapours in air. It is also a component of acid rain.
Acid rain consists of H2SO4and HNO3 that reduces the pH of rain water to 4.
Ozone layer lies in stratosphere about 25 to 30 km away from Earth’s surface.
Ozone layer protects Earth like a shield from harmful ultraviolet radiations of sunlight.
Chlorofluorocarbons destroy ozone molecules, depleting the ozone called ozone hole.
Depletion of ozone enables ultraviolet radiations of the Sun to reach the Earth; causing infectious diseases; changing the life cycle of plants, wind patterns.