Orbitals and Nucleus - Quick question

[Elpinetos]

Just a quick question - how come that for electrons we need probability orbitals, but for the nucleus we don't?
Is it because of the difference in mass? Or because of a bigger matter wavelength?
Can we really pinpoint the location of the nucleus or ist it just easier for textbooks to depict it like in the middle?
Or is it simply because of it's size?

 

[hilbert2]

The nucleons have some kind of orbitals too, but they are much more difficult to calculate than electronic orbitals because the inter-nucleon potential energy function is not known exactly. Also, the nucleus can usually be treated as a point-like object in electronic structure calculations because of the large difference in length scales. The nucleus is so small because neutrons and protons are much heavier than electrons and because the interaction between them is strong.

Also note that the orbital model of the atom is just an approximation that neglects electron correlation at least partially.

 

[jfizzix]

If you're interested in exactly what corrections there are to get a better model of the hydrogen atom (to start with), wikipedia has excellent articles on
fine structure:
http://en.wikipedia.org/wiki/Fine_structure
and hyperfine structure:
http://en.wikipedia.org/wiki/Hyperfine_structure

Fine structure and hyperfine structure are progrssively higher corrections to the energy levels of the hydrogen atom. One term in the fine structure (the Darwin term) accounts for the nucleus being of nonzero size.