This PSEB 7th Class Social Science Notes Chapter 3 Atmosphere and Temperature will help you in revision during exams.
PSEB 7th Class Social Science Notes Chapter 3 Atmosphere and Temperature
→ Atmosphere: The big protective layer surrounding the earth.
→ Composition of Atmosphere: Atmosphere is a mixture of different gases. Two gases are main Nitrogen (almost 78%) and Oxygen (almost 21%).
→ Layers of Atmosphere: Four layers.
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
→ Troposphere: This layer is the closest to the earth. All the happenings take place in the troposphere. This layer protects us from the dangerous ultra-violet rays of the sun.
→ Factors affecting the atmosphere: Three main factors affect the atmosphere
- Latitudes
- Height above the sea level
- Distance from the sea.
→ Global Warming: The increase in global temperatures brought about the increased emission of greenhouse gases into the atmosphere.
→ Troposphere: It is the lowermost layer of the atmosphere.
→ Weather: It is the description of the atmospheric conditions of a particular place at a particular time for a short period of time.
→ Climate: It is the composite or integrated picture of the weather conditions over a long period of time such as a season or a year.