Isotopes of californium Isotopes of californium Californium (Cf) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was Cf in 1950. There are 20 known radioisotopes ranging from Cf to Cf and one nuclear isomer, Cf. The longest-lived isotope is Cf with a half-life of 900 years. Californium-252 (Cf-252) undergoes spontaneous fission and is used in small sized neutron sources. Fission neutrons have an energy range of 0 to 13 MeV with a mean value of 2.3 MeV and a most probable value of
Naming of chemical elements Naming of chemical elements Chemical elements may be named from various sources: sometimes based on the person who discovered it, or the place it was discovered. Some have Latin or Greek roots deriving from something related to the element, for example some use to which it may have been put. All 118 discovered elements are confirmed and have a formal name and symbol, as decided by IUPAC. The last four names and symbols were added on November 28, 2016. Incidentally, at this moment there are no unconfirmed discoveries and all seven periods (rows) of the periodic table are completed. Element