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(III) polyborate can be made by autoclaving a californium(III) chloride solution in water with excess boric acid for a week at 240°C. This is then cooled slowly to room temperature for another three days. Water dissolves excess boric acid to leave insoluble crystals of the borate. The californium(III) polyborate solid undergoes a green fluorescence of 525 nm with ultraviolet light of wavelengths 365 or 420 nm. There is also an invisible near infrared fluorescence at 1020 nm induced by green light at 546 nm. Californium polyborate is dangerous because of the radioactivity of californium and its decay daughter curium. Between them these