1. Published by Pearson Education India Authored by Edgar Thorpe & Showick Thorpe PART 1:ATMOSPHERE [Section 4] Topics Covered Slide Numbers 4.1 Composition [2-3 ] 4.2 Atmospheric pressure [4] 4.3 Atmospheric Layers[5-6] 4.4 Winds[7-10]

2. Question 1: The most abundant element in the earth’s atmosphere is_________. Answer: Nitrogen Extra Fact Punch: Nitrogen accounts 78.09% in the earth’s atmosphere.

3. Question 2: As we move 50 km above the earth’s surface the atmosphere changes. At that height the atmosphere is composed of: Answer: Atomic oxygen, helium, hydrogen. Extra Fact Punch: At height of 50 km the earth’s atmosphere is composed of Nitrogen 78.09%, Oxygen (0.95%), Argon(0.93%), Minor Gases (0.03%) ( Carbon dioxide, hydrogen, neon, helium, methane, xenon, krypton, etc.)

4. Question 3: If atmospheric pressure refers to the weight of entire air column over a point then what is the air pressure at the sea level? Answer: 1033.6g cm square, this is referred to as one atmosphere. Extra Fact Punch: A litre of air weigh about 1.3 g.

5. Question 4: The layer of atmosphere close to earth’s surface is known as_______. Answer: Troposphere. Extra Fact Punch: It extends from sea-level to a height of about 15km.

6. Question 5: The magnetic belt of earth which is known as _________, extends to about 64,000 km above the earth’s surface. Answer: Magnetosphere. Extra Fact Punch: The outer boundary of the magnetosphere between the earth and the outer space is known as its magnetopause.

7. Question 6: The rotation of earth causes the deflection of winds then name types of winds? Answer: it is divided into 3 groups: (a) regular winds. (b) periodical winds. (c) variable winds. Extra Fact Punch: Wind movement is caused by the difference in air pressure on the earth’s surface.

8. Question 7: Westerlies are also known as ________. Answer: Roaring forties. Extra Fact Punch: The westerlies are regular winds which blow outside the tropics in the temperate zone.

9. Question 8: Other name to describe Chinook ________. Answer: Fohen. Extra Fact Punch: Chinook is a hot dry wind blowing on the east or leeward side of the rocky mountains in North America. As these winds descend from the mountains, they are pressed down and get heated. Similar winds on the north of the Apls (Europe) are called Fohen.

10. Question 9: What causes soil erosion (a) Sand or (b) Wind and Water? Answer: (b) Wind and water. Extra Fact Punch: Variable winds are responsible for cyclones and other local winds.