Chemical element "sulfur" over the British "sulphur". However, elements that are practical to sell in bulk in many countries often still have locally used national names, and countries whose national language does not use the Latin alphabet are likely to use the IUPAC element names. According to IUPAC, chemical elements are not proper nouns in English; consequently, the full name of an element is not routinely capitalized in English, even if derived from a proper noun, as in californium and einsteinium. Isotope names of chemical elements are also uncapitalized if written out, "e.g.," carbon-12 or uranium-235. Chemical element "symbols" (such as Cf
Californium compounds hexagonal structure. Californium(III) iodide (CfI) is a lemon-yellow solid that has a rhombohedral structure and sublimes at ~800 °C. Californium(III) oxyfluoride (CfOF) is prepared by hydrolysis of californium(III) fluoride (CfF) at high temperature. Californium(III) oxychloride (CfOCl) is prepared by hydrolysis of the hydrate of californium(III) chloride at 280–320 °C. Heating the sulfate in air at about 1200 °C and then reducing with hydrogen at 500 °C produces the sesquioxide (CfO). The hydroxide Cf(OH) and the trifluoride CfF are slightly soluble. Californium(III) oxychloride (CfOCl) was the first californium compound to be discovered. Californium(III) polyborate is unusual in that californium is covalently