Indefinite number of neutrons?

[bemigh]

I have a very basic question regarding the nucleus.

I understand why you can only have a limited number of protons within the nucleus - more and more protons within the nucleus will increase the coulomb potential and cause the nucleus to be unstable.

But why is this so for neutrons? Why couldn't I have an isotope of 50-O? The nuclear force is equally strong for n-n connections, as n-p, and p-p, so what's stopping the nucleus from having an a very large number of neutrons? When you look at a table of stable nuclides, it's pretty easy to see that most stable nuclides have equal #'s of protons and neutrons, but why is this needed? What am I missing?

Thanks

 

[hamster143]

Check this link:

http://en.wikipedia.org/wiki/Semi-empirical_mass_formula#Asymmetry_term

 

[malawi_glenn]

Also check out neutron drip line.

And also, n-n can not be bound.