How do we know that most of an atom is empty space? And since that is so, why can’t we just walk through solid objects?

Question

How do we know that most of an atom is empty space? And since that is so, why can’t we just walk through solid objects?

In: 13

Answer 1

We know that an atom is empty space because of experiments, especially shooting small stuff through the atom and seeing how much makes to the other side.

We do not cross stuff for the same reason that you can’t join two magnets on the same side, the outer part of atoms is all – and will mostly repel each other and will do it increasingly strongly the closer it gets.