Which gas is most abundant in Earth's atmosphere?

In which layer of the atmosphere does weather occur?

Which atmospheric layer contains the ozone layer?

Which gas in the atmosphere helps block harmful UV rays?

What happens to air pressure as altitude increases?

Which layer is the coldest part of the atmosphere?

The auroras (Northern and Southern Lights) occur in which atmospheric layer?

The outermost layer of the atmosphere is called:

Which gas is essential for human respiration?

Which instrument is used to measure atmospheric pressure?