Ununseptium

Ununseptium is the temporary name of an undiscovered chemical element in the periodic table that has the temporary symbol Uus and has the atomic number 117. Ununseptium can be referred to as eka-astatine.

History
Ununseptium has not yet been discovered. As of 2007, no attempt has been made to synthesise this element. The Joint Institute for Nuclear Research in Dubna, Russia has plans for the synthesis of ununseptium in the near future.

The most likely reactions, under discussion, are:


 * $$\,^{48}_{20}\mathrm{Ca} + \,^{249}_{97}\mathrm{Bk} \to \,^{297}_{117}\mathrm{Uus} ^{*} \to \,^{294,293}\mathrm{Uus} $$


 * $$\,^{50}_{22}\mathrm{Ti} + \,^{243}_{95}\mathrm{Am} \to \,^{293}_{115}\mathrm{Uus} ^{*} \to \,^{290,289}\mathrm{Uus}$$

Chemical Properties
Certain chemical properties, such as bond lengths, are predicted to differ from what one would expect based on periodic trends from the lighter halogens (because of relativistic effects). Ununseptium may show semimetal properties as well.