Nucleons in a nucleus are held together by attractive short range forces. These forces are stronger than columbic forces and act between neighbouring nucleons. These forces are charge independent.<br>Explain in one are two sentences why<br>(i) A large nucleus can not consist only of protons<br>(ii) All matter is not nuclear.

PLACEHOLDER ANSWER - the answer is two short explanations. (i) The nuclear force acts only between neighbouring nucleons, but the Coulomb repulsion acts between every pair of protons. In a large nucleus of protons alone, the total repulsion would exceed the attraction, so neutrons, which attract without repelling, are needed for stability. (ii) The nuclear force has a very short range, about the size of a nucleus, while atoms are far larger, so nuclei of neighbouring atoms are too far apart to attract each other and ordinary matter does not collapse into nuclear matter.