Tennessine 17 in the periodic table, below the five halogens; fluorine, chlorine, bromine, iodine, and astatine, each of which has seven valence electrons with a configuration of . For tennessine, being in the seventh period (row) of the periodic table, continuing the trend would predict a valence electron configuration of , and it would therefore be expected to behave similarly to the halogens in many respects that relate to this electronic state. However, going down group 17, the metallicity of the elements increases; for example, iodine already exhibits a metallic luster in the solid state, and astatine is often classified as
Bromine pentafluoride Bromine pentafluoride Bromine pentafluoride, BrF, is an interhalogen compound and a fluoride of bromine. It is a strong fluorination reagent. BrF finds use in oxygen isotope analysis. Laser ablation of solid silicates in the presence of bromine pentafluoride releases O for subsequent analysis. It has also been tested as an oxidizer in liquid rocket propellants and is used as a fluorinating agent in the processing of uranium. Bromine pentafluoride was first prepared in 1931 by the direct reaction of bromine with fluorine. This reaction is suitable for the preparation of large quantities, and is carried out at temperatures over with