Does gravity affect atoms?
Gravity affects atoms the same way it affects all other matter. Every atom creates its own gravitational field which attracts all other matter in the universe. If you put a lot of atoms together, like in a planet or a star, all of the little gravitational fields add together, creating a much stronger pull.
If you could hold an atom in your hand and drop it, it would fall to the ground, just like a book or a brick. In fact, if you could remove all the air from a room and drop an atom in a vacuum, it would fall to the ground at exactly the same rate as a book or a brick would. After all, a book or a brick is nothing more than a collection of atoms.
Steve Gagnon, Science Education Specialist (Other answers by Steve Gagnon)