sentence: Neutrons have no charge and protons are positively charged.
sentences_after: Because the nucleus is only made up of protons and neutrons it is positively charged. Things that have the same charge repel each other. Unless there was something else holding the nucleus together it could not exist because the protons would push away from each other. The nucleus is actually held together by a force called the strong nuclear force.
concept_name: neutron
headings: Atomic nucleus
categories: Nuclear physics Matter