Carbon–fluorine bond the molecule represented by CHX has a BDE of 115 kcal/mol for carbon–fluorine while values of 104.9, 83.7, 72.1, and 57.6 kcal/mol represent carbon–X bonds to hydrogen, chlorine, bromine, and iodine, respectively. The carbon–fluorine bond length is typically about 1.35 ångström (1.39 Å in fluoromethane). It is shorter than any other carbon–halogen bond, and shorter than single carbon–nitrogen and carbon–oxygen bonds, despite fluorine having a larger atomic mass. The short length of the bond can also be attributed to the ionic character/electrostatic attractions between the partial charges on carbon and fluorine. The carbon–fluorine bond length varies by several hundredths of
Origin and use of the term metalloid their ability to form oxyanions. A common oxyanion of sulfur, for example, is the sulfate ion SO. Many metals can do the same. Chromium, for instance, can form the chromate ion CrO. Berzelius' terminology was widely adopted although it was subsequently regarded by some commentators as counterintuitive, misapplied, incorrect or invalid. In 1825, in a revised German edition of his "Textbook of Chemistry," Berzelius subdivided the metalloids into three classes. These were: constantly gaseous 'gazolyta' (hydrogen, nitrogen, oxygen); real metalloids (sulfur, phosphorus, carbon, boron, silicon); and salt-forming 'halogenia' (fluorine, chlorine, bromine, iodine). In 1844, Jackson gave the meaning of 'metalloid'