208Pb + ⁷⁰Zn ²⁷⁷Uub + ¹n

The element was synthesized in 2000 and 2004 by Andre Georgievich Popeko, Alexander Vladimirovich Yeremin, A.N. Andreyev at the Joint Institute for Nuclear Research in Dubna, Russia.

In May 2006 in the Joint Institute for Nuclear Research the synthesis of this element was confirmed by another method.  The isotope ²⁸²Uub was identified as a final product of this series of alpha decays:

²⁹⁴Uuo ²⁹⁰Uuh ²⁸⁶Uuq ²⁸²Uub.

Ununoctium Ununhexium Ununquadium Ununbium

It was found that the final nucleus undergoes spontaneous fission.  Spontaneous fission products are much smaller and irregular.

Characteristics

Ununbium, or eka-mercury, is a temporary IUPAC systematic element name for a chemical element in the periodic table that has the temporary symbol Uub and the atomic number 112.   Element 112 is one of the superheavy elements.  Various speculations have been generated regarding its possible physical appearance, such as:

(1) Following periodic trends, one might expect a liquid metal more volatile than mercury.

(2) Some experimental work so far indicates a gas and theoretical considerations also point to properties more similar to a noble gas than to mercury.

(3) A synthetic element not present in nature, appearance unknown, probably metallic solid.

(4) probably silvery-white or metallic-gray liquid or colorless gas.

Known members of group 12 all react with oxygen and sulfur directly to form the oxides and sulfides.  Mercury (II) oxide, HgO, can be decomposed by heat to the liquid metal.  Mercury also has a well known affinity for sulfur.  Therefore, element 112 is expected to form an analogous oxide and sulfide.  In their halogen chemistry, all the metals form the ionic difluoride upon reaction with fluorine.  The other halides are known but for mercury, the soft nature of the Hg(II) ion leads to a high degree of covalency and HgCl₂, HgBr₂ and HgCl₂ are low-melting, volatile solids.  Therefore, element 112 is expected to form an ionic fluoride, but volatile halides.  In addition, mercury is well known for its alloying properties, with the concomitant formation of amalgams, especially with gold and silver.  It is also a volatile metal and is monatomic in the vapor phase.  Element 112 is also predicted to be a volatile metal which readily combines with gold to form metal-metal bond.

Isotopes

Ununbium's most stable isotope, ununbium-285, has a half-life of about 10 minutes.  It decays into darmstadtium-281 through alpha decay.

Since only a few atoms of ununbium have ever been produced, it currently has no uses outside of basic scientific research.