Number of protons and neutrons per shell?

[the riddick25]

before i start i wanted to make it clear that this is NOT homework. its just a quick question which puzzled me and my friend

In the shell model of the nucleus. i found a statement that said that since both neutrons and protons are fermions, there are restricted to 2 of each at each energy level.
but when reading something else, it said there could only be 2 at each energy level (not 2 of each)

so could someone please tell me the correct answer, are there 2 protons and 2 neutrons per shell (making 4), or just a total of 2.

thanks :)

 

[ansgar]

neutron and proton are distinguishable fermions

you must have missinterpreted, the real statement is max one indistinguishable fermion per quantum state. Every indistinguishable fermion must have an unique set of quantum numbers.