The atmosphere is composed of a
mixture of _______________,
_____________ ____________,
and tiny___________________.
Thank you for using the Jiskha Homework Help Forum. The origin of our atmosphere is still open to a great deal of speculation. One theory is that the first atmosphere probably consisted of helium, hydrogen, ammonia and methane. The earth's second atmosphere probably consisted of water vapor, carbon dioxide, and nitrogen.
The above information (as well as much more) comes from:
http://ess.geology.ufl.edu/HTMLpages/ESS/GLY1033_notes/lecture1.html
Here are the layers: http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html
http://en.wikipedia.org/wiki/Earth's_atmosphere