Described as an electron cloud, the quantum model of the atom is the result of de Broglie waves and Heisenberg’s uncertainty principle The structure of the nucleus is defined by its two nucleons, the neutron and proton

Rutherford’s gold foil experiment provided evidence that the atom is composed of a small, dense nucleus with electrons occupying the mostly empty space around it The Bohr model of the atom describes electrons existing in discrete orbits, with discrete energies emitted and absorbed as the electrons decrease and increase in orbital energy

atom — composed of a small, dense nucleus with electrons occupying the mostly empty space around it. quantum model of the atom — the result of de Broglie waves and Heisenberg’s uncertainty principle. structure of the nucleus — defined by its two nucleons, the neutron and proton. nucleons — particles found inside nuclei.