The discoveries of americium, berkelium, and californium followed soon. In experiments during 1949-1950, they produced and identified elements 97 (berkelium) and 98 (californium). Thus, the symbols for californium and einsteinium are Cf and Es. Most of these applications exploit the property of certain isotopes of californium to emit neutrons. The isotopes of californium range in mass number from 237 to 256. Californium is a radioactive chemical element with the symbol Cf and atomic number 98. Phelps has also studied electrodeposition with californium-252 for the Californium Rare Isotope Breeder Upgrade project. Californium is produced in nuclear reactors and particle accelerators. Ionizing radiation emitted by californium on bone and in the liver can cause cancer. By 1995, the HFIR nominally produced of californium annually. The first experiment with californium in concentrated form occurred in 1958. ORNL resumed californium production in spring 2008. Once in the body, only 0.05% of the californium will reach the bloodstream. Californium (Cf) is an artificial element, and thus a standard atomic weight cannot be given. Compounds of californium are dominated by the +3 oxidation state.