COT 2

1. What do you call to a mixture of gases and particles that surround a planet, held

by gravity?

• A. Atmosphere

• B. Blanket

• C. Greenhouse

• D. Ozone

2. What layer of the atmosphere that starts just above the troposphere and extends

to about 50 km?

• A. Exosphere

• B. Mesosphere

• C. Stratosphere

• D. Thermosphere

3. In which atmospheric layer is Aurora borealis found?

• A. Troposphere

• B. Stratosphere

• C. Mesosphere

• D. Thermosphere

What is the most abundant element in the Earth's atmosphere?

• A. Argon

• B. Carbon dioxide

• C. Nitrogen

• D. Oxygen

5. Which of the following is considered to be as the coldest layer?

• A. Ionosphere

• B. Mesosphere

• C. Stratosphere

• D. Thermosphere