Atomic considerations

Abstract

Before discussing nuclear fission or fusion, it is important to understand the atomic nucleus. An atom comprises positively charged protons and neutral neutrons within the nucleus, and a negatively charged electron cloud surrounding the nucleus balancing the charge, i.e. in a neutral state the proton and electron count are identical. Protons and neutrons are baryons and thus composed of quarks, but the arrangement is different. The proton has two up quarks and one down quark, whereas the neutron has one up and two down, with each species held together by the strong nuclear force.