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
Biological aspects of fluorine Biological aspects of fluorine Biological aspects of fluorine describes the effects of fluorine-containing compounds with life. Fluorine (F) itself is very rare in everyday life, but hundreds of fluorine-containing compounds occur as minerals, medicines, pesticides, and materials. Naturally occurring organofluorine compounds are extremely rare. Nonetheless, twenty percent of all commercialized pharmaceuticals contain fluorine, examples being Lipitor and Prozac. Manmade fluorinated compounds have also played a role in several noteworthy environmental concerns. Chlorofluorocarbons, once major components of numerous commercial aerosol products, have proven damaging to Earth's ozone layer and resulted in the wide-reaching Montreal Protocol (though in truth the chlorine in