112
  Uub  
277.000000
Ununbium

Name: Ununbium
Symbol: Uub
Atomic Number: 112
AtomicWeight: 277.000000
Family: Transition Metals
CAS RN: 54084-26-3
Description: A synthetic element not present in nature, appearance unknown, probably metallic solid
State (25°C): Unknown (Synthetic)
Oxidation states:
Valence Electrons: 5f146d107s2

Boiling Point:  unknown
Melting Point:
unknown
Electrons Energy Level: 2, 8, 18, 32, 32, 18, 2
Isotopes: 9 + None Stable
Heat of Vaporization: unknown
Heat of Fusion: unknown
Density: unknown
Specific Heat: unknown
Atomic Radius: unknown
Ionic Radius: unknown
Electronegativity: unknown
Vapor Pressure: unknown

History

Ununbium was first created on February 9, 1996 by Sigurd Hofmann, Victor Ninov, Fritz Peter Hessbuger, Peter Armbruster, H. Folger, Gottfried Münzenberg, H.J. Schött et al. at the Gesellschaft fur Schwerionenforschung (GSI) in Darmstadt, Germany. 

Two decay chains of the isotope 277Uub were observed in irradiations of 208Pb targets with 70Zn projectiles of 343.8 MeV kinetic energy in a heavy ion accelerator. This produced atoms of 277Uub, an isotope with a half-life of about 0.24 milliseconds (0.00024 seconds).

208Pb + 70Zn rarrow.gif (63 bytes) 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 rarrow.gif (63 bytes) 290Uuh rarrow.gif (63 bytes) 286Uuq rarrow.gif (63 bytes) 282Uub.

Ununoctium rarrow.gif (63 bytes) Ununhexium rarrow.gif (63 bytes) Ununquadium rarrow.gif (63 bytes) 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.

1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f14
6s2 6p6 6d10
7s2

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.

atom.gif (700 bytes)

Isotope  
Atomic Mass
 
Half-Life
277Uub 277.16394 0.24 ms
278Uub 278.16431 ~10 ms
279Uub 279.16655 ~0.1 seconds
280Uub 280.16704 ~1 seconds
281Uub 281.16929 ~10 seconds
282Uub 282.16977  
283Uub 283.17179 ~5 minutes
284Uub 284.17238  
285Uub 285.17411 10 minutes

Transition Metals
Group 3
(IIIB)
4
(IVB)
5
(VB)
6
(VIB)
7
(VIIB)
8
(VIIIB)
9
(VIIIB)
10 (VIIIB) 11
(IB)
12
(IIB)
Period 4 21
Sc
44.95
22
Ti
47.86
23
V
50.94
24
Cr
51.99
25
Mn
54.93
26
Fe
55.84
27
Co
58.93
28
Ni
58.69
29
Cu
63.54
30
Zn
65.39
Period 5 39
Y
88.90
40
Zr
91.22
41
Nb
92.90
42
Mo
95.94
43
Tc
98.00
44
Ru
101.0
45
Rh
102.9
46
Pd
106.4
47
Ag
107.8
48
Cd
112.4
Period 6 57
La
138.9
72
Hf
178.4
73
Ta
180.9
74
W
183.8
75
Re
186.2
76
Os
190.2
77
Ir
192.2
78
Pt
195.0
79
Au
196.9
80
Hg
200.5
Period 7 89
Ac
227.0
104
Rf
261.0
105
Db
262.0
106
Sg
266.0
107
Bh
264.0
108
Hs
269.0
109
Mt
268.0
110
Ds
269.0
111
Rg
272.0
112
Uub
277.0