Ununennium, or element 119, is a predicted chemical element. Its symbol is Uue. Ununennium and Uue are substitute names made by the IUPAC, (meaning "one-one-nine-ium" in Latin) until permanent names are made. Ununennium is the element with the smallest atomic number that has not been created yet. Qualities of Ununennium are unknown, but many are predicted. It is predicted all isotopes will be radioactive. It is thought to be an alkali metal.
|Pronunciation||// (listen) |
|Alternative names||element 119, eka-francium|
|Ununennium in the periodic table|
|Atomic number (Z)||119|
|Group||group 1: hydrogen and alkali metals|
|Electron configuration||[Og] 8s1 (predicted)|
|Electrons per shell||2, 8, 18, 32, 32, 18, 8, 1 (predicted)|
|Phase at STP||unknown (could be solid or liquid)|
|Melting point||273–303 K (0–30 °C, 32–86 °F) (predicted)|
|Boiling point||903 K (630 °C, 1166 °F) (predicted)|
|Density (near r.t.)||3 g/cm3 (predicted)|
|Heat of fusion||2.01–2.05 kJ/mol (extrapolated)|
|Oxidation states||(+1), (+3) (predicted)|
|Electronegativity||Pauling scale: 0.86 (predicted)|
|Atomic radius||empirical: 240 pm (predicted)|
|Covalent radius||263–281 pm (extrapolated)|
|Crystal structure|| body-centered cubic (bcc)|
|Naming||IUPAC systematic element name|
Many attempts have been made by American, German, and Russian teams to make ununennium but all have failed. Japanese and Russian teams plan to work on it in 2019 and 2020.
Ununennium's spot on the periodic table is a sign that it may be similar to lighter elements such as lithium, sodium, potassium, rubidium, caesium, and francium; however, some of its properties may be different from what is expected. For example, ununennium might be less reactive than caesium and francium and will behave more like potassium or rubidium.
As of 2022, it has yet to be created and therefore has no use.
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