The composition of the atmosphere is approximately 80 per cent nitrogen and 20 per cent oxygen by mass. at what height above the surface of the earth would the atmosphere become 90 per cent nitrogen and 10 per cent oxygen by mass? assume that the temperature of the atmosphere is constant at 25 c. what is the pressure of the atmosphere at that height?

How would i answer this for an exam?

If you could drill a hole straight to the center of the earth, and keep track of what the hole is going through, youwould find: a) you would go through one sort of material, and then a different, denser material, and then a still-different, still-denser material, because the planet is made of concentric layers, sort of like an onion. b) you would go through one sort of material all the way to the center, because the planet is all mixed up. c) if your hole started at the north pole, you would go through different layers of different materials, but ifyour hole started at the equator, you would go through one sort of material all the way to the center. d) if your hole started at the equator, you would go through different layers of different materials, but if yourhole started at the north pole, you would go through one sort of material all the way to the center. e) you would strike diet pepsi when you got to the center.

Which barrier to economic development is shown in the following examples?