How many atoms are there in the universe

Well, I can tell you that there aren't an infinite amount of atoms out there, but there are more than we can count, like in this video at 1:20 http://www.youtube.com/watch?v=zn7-fVtT1… The universe is expanding, like everyone else said, but that doesn't mean that the amount of atoms is growing. Sure the Universe is expanding, but the amount of empty space, space meaning nothing, is expanding. The amount of atoms are staying the same, just the size is changing. So, that's basically it in a nut shell, without getting way to nerdy. Hope it helped!

As Kelc said, about 10^80 atoms in the observable Universe by current estimates, or
100 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000

Infinity
According to the many worlds therey for every possible outcome there is a parallel universe with that outcome so with infinite universes there is infinate atoms

About 10 raised to the 80th power (10^80) within our "event horizon".

The Universe, however, is known to be bigger than our event horizon, perhaps much, much bigger, perhaps infinite.

There is no possible way to ever figure it out, the number could be growing as well. I couldn't even give you an estimate because even the earth alone is made of such a large number

Infinity....... And beyond!!!

way more than what can be written as a understandable number

there are 42 atoms in the universe I counted them last week.