i) The layer of atmosphere just above the earth is known as
a) troposphere b) thermosphere c) stratosphere d) mesosphere
ii) The ratio of nitrogen to oxygen in the air is
a) 1:4 b) 4:1 c) 3:1 d) 1:2
iii) The gas present in the air which turns limewater milky is
a) Oxygen b) Nitrogen
c) Argon d) Carbon dioxide
iv) The oxygen present in the air is used for
a) respiration b) burning c) extinguish fire d) both (a) and (b).
v) Air is used for
a) separating husk from grains b) flying birds
c) dispersal of seeds d) all of these.
Answers
Answer:
1)The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere and thermosphere. A further region at about 500 km above the Earth's surface is called the exosphere.
2)The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of lots of other gases, too, such as carbon dioxide, neon, and hydrogen
3)Carbon dioxide reacts with limewater (a solution of calcium hydroxide, Ca(OH) 2), to form a white precipitate (appears milky) of calcium carbonate, CaCO 3.
4)Plants and animals use oxygen present in the air for respiration. Oxygen is also used for combustion. This oxygen is replaced by the plants during photosynthesis. This cycle repeats balancing the volume of oxygen in the air.
5)Air is important for living things.
Breathing is part of a process called respiration. During respiration, a living thing takes in oxygen from the air and gives out carbon dioxide. This process gives animals and plants the energy to eat, grow, and live life!
Answer:
The troposphere is 0-10km above the earth, while others thermosphere and stratosphere and mesosphere is 10km and above.
Explanation: