Tennessine astatine is estimated to be between 6.2 and 6.5 g/cm. The known isotopes of tennessine, Ts and Ts, are too short-lived to allow for chemical experimentation at present. Nevertheless, many chemical properties of tennessine have been calculated. Unlike the previous group 17 elements, tennessine may not exhibit the chemical behavior common to the halogens. For example, fluorine, chlorine, bromine, and iodine routinely accept an electron to achieve the more stable electronic configuration of a noble gas, obtaining eight electrons (octet) in their valence shells instead of seven. This ability weakens as atomic weight increases going down the group; tennessine would
Bromine pentafluoride an excess of fluorine: For the preparation of smaller amounts, potassium bromide is used: This route yields bromine pentafluoride almost completely free of trifluorides and other impurities. Bromine pentafluoride reacts violently with water, but when moderated by dilution with acetonitrile, it will form bromic acid and hydrofluoric acid, simple hydrolysis products: It is an extremely effective fluorinating agent, converting most uranium compounds to the hexafluoride at room temperature. Bromine pentafluoride is severely corrosive to the skin, and its vapors are irritating to the eyes, skin, and mucous membranes. Exposure to 100 ppm for a few minutes is lethal to most