This question already has an answer here:
All matter has a gravitational pull, a ball, a rock, a planet and a star - the bigger the matter the more it affects the space fabric around it thus having a greater gravitational pull.
I see black holes in the same kind of concept - matter that warps the space fabric/time around it - however as we can physically see a ball, a rock, a planet and a star I fail to visualize what would be the matter that continues a black hole to operate because we cannot see any physical element to it.
A black hole is cause when a star implodes on itself and crushes its self to an extent that gravity has such an effect on space time that we know of nothing that produce such a force.
What I would like to know is:
1: Is there a known "bottom" of a black hole? If so, what happens to all of the matter it swallows? surely it would be impossible to crush something so small that it physically no longer exists - where would it go then?
2: How small does the core of a collapsed star crush itself into? i.e the size of an atom or smaller?