alpha-particle scattering experiment; evidence of a small charged nucleus

simple nuclear model of the atom; protons, neutrons and electrons

relative sizes of atom and nucleus

proton number; nucleon number; isotopes; notation \(^A_ZX \) for the representation of nuclei

strong nuclear force; short-range nature of the force; attractive to about 3 fm and repulsive below about 0.5 fm

1 fm = 10^–15 m

radius of nuclei; \(R = r_0A^{1/3} \) where r₀ is a constant and A is the nucleon number

mean densities of atoms and nuclei.