I What is the size of neutrons in a neutron star?

No. However, it squashes the electron cloud onto the nucleus were they neutralize the protons. What you are left with is an atom all squshed into the nucleus which in turn is madeup of neutrons only. Further, because neutrons don't mind been near other neutrons and the pressure is insanely high, basically the entire star collapses into a gargantuan size nucleus, which is madeup of densely packed neutrons only. The size of this nucleus is really huge by nuclear sizes. It measures no less than 11km and no more than 11.5km in diameter, depending of how closed the neutrons are squeezed. The mass is even more mesmerizing! 1 - 2 Solar masses, all neatly packed in an 11km ball! I hope this helps.