Ununennium





Ununennium, or eka-francium, is the temporary name of an undiscovered chemical element in the periodic table that has the temporary symbol Uue and has the atomic number 119 , with a predicted significant atomic mass of 316. Like other alkali metals, it would most likely be extremely reactive with water.

Element 119 would be the first element in the eighth period of the periodic table.

History
The synthesis of element 119 was attempted in 1985 by bombarding a target of einsteinium-254 with calcium-48 ions at the superHILAC accelerator at Berkeley, California. No atoms were identified, leading to a limiting yield of 300 nb.


 * $$\,^{254}_{99}\mathrm{Es} + \,^{48}_{20}\mathrm{Ca} \to \,^{302}_{119}\mathrm{Uue} ^{*} \to \

$$ no atoms

It is highly unlikely that this reaction will be useful given the extremely difficult task of making sufficient amounts of Es-254 to make a large enough target to increase the sensitivity of the experiment to the required level.