However, electrons aren’t really particles (which is why it’s impossible to actually specify their size); they’re waves. Electrons are more like the “ringing” of the bell and less like a fly buzzing around the bell. The math that describes the “quantum wave function” of electrons in atoms and the math that describes vibrations in a bell have some things in common. In quantum physics things tend spread out between a lot of states (in this case those different states include different positions). The atom picture is from here.