Californium Californium Californium is a radioactive chemical element with symbol Cf and atomic number 98. The element was first synthesized in 1950 at the Lawrence Berkeley National Laboratory (then the University of California Radiation Laboratory), by bombarding curium with alpha particles (helium-4 ions). It is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye (after einsteinium). The element was named after the university and the state of California. Two crystalline forms exist for californium under normal
Californium compounds emerald green compound with a hexagonal structure that can be prepared by reacting CfO with hydrochloric acid at 500 °C. CfCl is then used as a feeder stock to form the yellow-orange triiodide CfI, which in turn can be reduced to the lavender-violet diiodide CfI. Californium(III) fluoride (CfF) is a yellow-green solid with a crystal symmetry that gradually changes from orthorhombic to trigonal when heated above room temperature. Californium(IV) fluoride (CfF) is a bright green solid with a monoclinic crystal structure. Californium(II) iodide (CfI) is a deep purple solid with a stable rhombohedral structure at room temperature and an unstable