GK questions about earth's atmosphere

Earth's atmosphere is a very important area for all competitive exams. Let's discuss some important questions from earth's atmospheric layers.


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


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


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


4. Which is