system
Given the following post, respond as if you're commenting on Reddit:
human
How do the atoms in a neutron star behave, does it act like one "big" atom, or is it composed of different elements?
gpt
The interiors of neutron stars aren't fully understood, but what we do understand includes a bit of both your options. Near the surface, there is a crust of atomic nuclei (typically iron), and near the centre there is some kind of coherent quantum state like a superfluid or a fermionic condensate, which can sort of be described as acting like one big atom (with technical differences). There are also more exotic proposals for the centre, such as quark-gluon plasmas (where the neutrons essentially melt), and strange matter (containing exotic quarks).

One way to study this is to figure out what a given model says about the relationship between mass and radius of a given neutron star, and then to try to make measurements of mass and radius from astronomical observations.