The Elements (07Nov00):

californium
Symbol: Cf
Atomic number: 98
Atomic weight: (249)
Radioactive metallic transuranic element. Belongs to actinoid series.
Cf-251 has a half life of about 700 years. Nine isotopes are known.
Cf-252 is an intense neutron source, which makes it an intense
neutron source and gives it a use in neutron activation analysis
and a possible use as a radiation source in medicine. First produced
by Glenn T. Seaborg and associates in 1950.