Chemical element "Sb" (stibium) for antimony. Chemical symbols are understood internationally when element names might require translation. There have sometimes been differences in the past. For example, Germans in the past have used "J" (for the alternate name Jod) for iodine, but now use "I" and "Iod". The first letter of a chemical symbol is always capitalized, as in the preceding examples, and the subsequent letters, if any, are always lower case (small letters). Thus, the symbols for californium and einsteinium are Cf and Es. There are also symbols in chemical equations for groups of chemical elements, for example in comparative formulas.
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