Are atoms composed of smaller things? Do atoms have structure? From when Dalton proposed the scientific theory that matter is composed of atoms, at the start of the 19th century, exactly these questions have been asked … and many scientists tried to answer them …
Today, a lot of people have the idea that atomic structure is like the solar system, with the atomic nucleus as the Sun, and electrons as planets in orbit around the nucleus; this is the Rutherford atom, or perhaps the Bohr atom … well, if you regard science as, among other things, a set of tools to test ideas like this, then the Rutherford atom does not describe atomic structure (or at least not consistently).
Today, the best description of atomic structure is one totally dependent on the mathematics of quantum mechanics. And what follows from this? Well, for one thing, any ‘word picture’ description of atomic structure will be at least somewhat inaccurate, if not downright misleading!
So, yes, the nucleus contains the protons and neutrons, occupies a tiny fraction of the volume of the atom (but co