These so-called monoisotopic elements are beryllium, fluorine, sodium, aluminum, phosphorus, scandium, vanadium, manganese, cobalt, arsenic, rubidium, yttrium, niobium, rhodium, indium, iodine, cesium, lanthanum, praseodymium, europium, terbium, holmium, thulium, lutecium, rhenium, and gold.