Here's why:

* Electrons don't orbit the nucleus like planets around a sun. They exist in a region of space called an electron cloud, where their exact location is uncertain. This cloud is defined by orbitals, which represent the probability of finding an electron at a given point.

* The nucleus is incredibly small compared to the overall size of the atom. Imagine a stadium as the atom, the nucleus would be like a pea in the center.

* Electromagnetic forces hold the atom together. The positive charge of the nucleus attracts the negative charge of the electrons, keeping them bound to the atom.

So, while we might picture electrons whizzing around the nucleus, the reality is much more complex and abstract. The space between them is mostly empty, but it's governed by powerful forces that keep the atom intact.