Standard State: solid at 298 K
Californium is the sixth transuranium element and was produced by Thompson, Street,
Ghiorso, and Seaborg in 1950. Californium should be handled with care because it is a radioactive rare earth metal
named after the state of California and the University of California. It has been
suggested that Californium is produced in certain stellar explosions, such as a supernova,
but is questionable.