How many different uncharged (neutral) stable hydrogen atoms can you build?

A stable hydrogen atom consists of one proton and one electron, and since hydrogen has only one proton, there is essentially only one type of neutral hydrogen atom. However, hydrogen does have isotopes—protium (1 proton), deuterium (1 proton and 1 neutron), and tritium (1 proton and 2 neutrons)—but these isotopes differ in their nuclear composition. Therefore, while you can have different isotopes of hydrogen, the fundamental neutral hydrogen atom remains the same. Thus, you can build one type of uncharged stable hydrogen atom, which is protium, but there are two isotopes (deuterium and tritium) that are also stable in their own right.