If the universe expands fast enough to rip atoms apart, what will happen to black holes? Would they rip apart too? What would that be like? Would they expand along with the universe's expansion, or would their gravitational force be able to resist it?
The universe won't expand fast enough to rip atoms apart, but if dark energy turns out to be a fact it will expand fast enough to avoid gravitational collapse. Black holes won't be ripped apart, they will just carry on as normal, as will the galaxies they belong to. But as space expands the galaxies will move further and further apart, going their own separate ways with not enough gravity to keep them together, eventually fading away into the black nothingness of space. Further research may mean that dark energy will have to be revised or reinterpreted, so at the present time a collapsing, blue shifted universe can't be completely ruled out.