radiochlorine: a radioactive isotope of chlorine
chlorine: a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water)
rutherford atom: first modern concept of atomic structure; all of the positive charge and most of the mass of the atom are contained in a compact nucleus; a number of electrons (equal to the atomic number) occupy the rest of the volume of the atom and neutralize the positive charge