Why does the Earth's atmosphere contain much more nitrogen than ...

[kfurse]

Why does the Earth's atmosphere contain much more nitrogen than hydrogen?
 
  What will be an ideal response?

Question 2

If the hypothesis tracing the extinction of the dinosaurs to an impact is correct, the dinosaurs died off largely because ________.
 
  A) the impact caused massive earthquakes worldwide
  B) radiation from iridium in the asteroid caused the dinosaurs to die of cancer
  C) of global climate effects initiated by dust and smoke that entered the atmosphere after the impact
  D) of injuries suffered from direct hits of pieces of the asteroid or comet

[ilianabrrr]

Answer to Question 1

Heavier nitrogen can be retained by our gravity, whereas lighter hydrogen leaks away into space, because its average molecular speed at the Earth's temperature exceeds the Earth's escape velocity.

Answer to Question 2

C

[kfurse]

YES! Correct, THANKS for helping me on my review

[kjohnson]

Excellent