1. Which is the most abundant gas in earth's atmosphere ?
Nitrogen

2. What is the percentage of oxygen in earth's atmosphere ?
21 %

3. Which is the most abundant noble gas in earth's atmosphere ?
Argon

4. Which is the lower most layer in earth's atmosphere ?
Troposphere

5. Weather phenomena like cloud, rain, snow, storm etc are formed in which atmospheric layer of earth ?
Troposphere

6. In which atmospheric layer the phenomenon Aurora Borealis occurs ?
Thermosphere

7. Which is the device used to measure atmospheric pressure?
Barometer