There are dozens, though the four (solid, liquid, gas, plasma) are considered the “fundamental” states.
But non-Newtonian fluids (like cornstarch mixed with water) and stuff like superconductors don’t fit into the simpler definitions, so there are lots (and even more proposed).
I was going to add stuff like the crap inside neutron stars, and quark-gluon plasma, but figured since it wasn’t the same stuff anymore it’s not really a phase. If you take those two items and just relieve the pressure and temperature, you’re not guaranteed to get what you started with.
There are dozens, though the four (solid, liquid, gas, plasma) are considered the “fundamental” states.
But non-Newtonian fluids (like cornstarch mixed with water) and stuff like superconductors don’t fit into the simpler definitions, so there are lots (and even more proposed).
I was going to add stuff like the crap inside neutron stars, and quark-gluon plasma, but figured since it wasn’t the same stuff anymore it’s not really a phase. If you take those two items and just relieve the pressure and temperature, you’re not guaranteed to get what you started with.