6 multiple choice questions about the atmosphere(please help really importent)?

Question

1. the volume of nitrogen in Earth's atmosphere at sea level is about

a. 4% b.21% c.78% d.96%

2. the secon lightest element is

a.neon b.oxygen c.hydrogen d.helium

3. the air tep in the tropopause ove the continental usa is about

a.-30 C b.-60 C c.-180 c d.-273 C

4. The part of earths atmosphere the shields earth from harmful ultraviolet radiotion is called the

a. equatorial bulge b.ionic layer c.ozone layer d. protective layer

5.the layer of the earth the reflects radio waves back to earth is called the

a. ionosphere b.radition zone c. aurora borealis d. ozone layer

6. which of the following causes the aurora borealis?

a. gases escaping the earth

b.particles reflected off the moon

c. particles given off by the sun

d. radiotion from earth's magnatic field

Answer 1

1 C

2 D

3 B

4 C

5 A

6 C