Come To Learn – Social Science Resources for Classes 6 to 10

  Important Question Answers for the Class 9-Social Science Chapter 3-  Atmosphere and Climate ***************************** The Big Questions: 1. What is the composition of the atmosphere? The atmosphere contains 78% nitrogen and 21% oxygen . It also contains argon, carbon dioxide and other gases in small amounts. Water vapour and dust particles help in cloud formation and rainfall. 2. How do the different layers of the atmosphere affect the Earth? Troposphere: It contains air and produces weather conditions. Stratosphere: Its ozone layer blocks harmful solar radiation. Mesosphere: It burns up most meteorites entering the atmosphere. Thermosphere: It supports radio communication and produces auroras. Exosphere: Light gases escape into space from this layer. 3. What is the mechanism of monsoon?  Monsoons are seasonal winds caused by unequal heating of land and sea. In summer, low pressure develops over land and high pressure over the ocean. Moist south-west winds bl...

  Important Question Answers for the Class 9-Social Science Chapter 2- Shaping of the Earth's Surface ***************************** The Big Questions:  (These questions are as per new textbook) Q1. What shapes the Earth’s surface? Answer:- The Earth’s surface is shaped by two main kinds of forces: 1. Internal forces originate inside the Earth. They are caused by heat and movements within the Earth.  2. They produce: Earthquakes, Volcanic eruptions, Folding, Faulting. These forces build mountains, valleys, plateaus and ocean basins. 3. External forces work on the Earth’s surface. They include: Weathering, Erosion, Transportation, Deposition 4. Running water, sea waves, glaciers, wind and underground water act as agents of change. 5. They wear down high areas and deposit material in low areas. Q2. What is plate tectonics? What are the effects of plate movement? Answer:- 1. Plate tectonics is the theory that the Earth’s outer layer is divided into large and small tecton...