Nihonium

Template:Elementbox header Template:Elementbox series Template:Elementbox groupperiodblock Template:Elementbox appearance Template:Elementbox atomicmass gpm Template:Elementbox econfig Template:Elementbox epershell Template:Elementbox phase Template:Elementbox cas number Template:Elementbox isotopes begin |- ! style="text-align:right;" | ²⁸⁴Uut | style="text-align:center;" | syn | style="text-align:right;" | 0.49 s | alpha | style="text-align:right;" | ²⁸⁰Rg |- ! style="text-align:right;" | ²⁸³Uut | style="text-align:center;" | syn | style="text-align:right;" | 0.10 s | alpha | style="text-align:right;" | ²⁷⁹Rg |- ! style="text-align:right;" | ²⁸²Uut | style="text-align:center;" | syn | style="text-align:right;" | 73 ms | alpha | style="text-align:right;" | ²⁷⁸Rg |- ! style="text-align:right;" | ²⁷⁸Uut | style="text-align:center;" | syn | style="text-align:right;" | 0.34 ms | alpha | style="text-align:right;" | ²⁷⁴Rg Template:Elementbox isotopes end Template:Elementbox footer

Ununtrium (Template:PronEng), or eka-thallium, is the temporary name of a synthetic element in the periodic table that has the temporary symbol Uut and has the atomic number 113. It has been synthesised both directly in "cold" and "warm" fusion reactions. It was first observed in the decay of ununpentium. Only eight atoms of ununtrium have been observed to date. Following periodic trends it is expected to be a soft, silvery metal.

Discovery Profile

The first report of ununtrium was in August 2003 when it was identified as a decay product of ununpentium. These results were published on February 1, 2004, by a team composed of Russian scientists at Dubna (Joint Institute for Nuclear Research), and American scientists at the Lawrence Livermore National Laboratory.

$\,_{20}^{48}\mathrm {Ca} +\,_{95}^{243}\mathrm {Am} \to \,^{288,287}\mathrm {Uup} \to \,^{284,283}\mathrm {Uut} \to \$

On July 23, 2004, a team of Japanese scientists at RIKEN detected a single atom of ²⁷⁸Uut using the cold fusion reaction between Bismuth-209 and zinc-70. They published their results on September 28, 2004.

$\,_{30}^{70}\mathrm {Zn} +\,_{83}^{209}\mathrm {Bi} \to \,_{113}^{279}\mathrm {Uut} ^{*}\to \,_{113}^{278}\mathrm {Uut} +\,_{0}^{1}\mathrm {n}$

The RIKEN team produced a further atom on April 2, 2005, although the decay data was different from the first chain, and may be due to the formation of a meta-stable isomer.

The Dubna-Livermore collaboration has strengthened their claim for the discovery of ununtrium by conducting chemical experiments on the decay daughter ²⁶⁸Db. In experiments in Jun 2004 and Dec 2005, the Dubnium isotope was successfully identified by milking the Db fraction and measuring any SF activities. Both the half-life and decay mode were confirmed for the proposed ²⁶⁸Db which lends support to the assignment of Z=115 and Z=113 to the parent and daughter nuclei.

Naming

Current Names

The element with Z=113 is historically known as eka-thallium. Ununtrium (Uut) is a temporary IUPAC systematic element name. Research scientists usually refer to the element simply as element 113 (E113).

Proposed Names by Claimants

Claims to the discovery of element 113 have been put forward by Dmitriev of the Dubna team and Morita of the RIKEN team. The JWP will decide to whom the right to suggest a name will be given. The IUPAC have the final say on the official adoption of a name. The table below gives the names that the teams above have suggested and which can be verified by press interviews.

Group	Proposed Name	Proposed Symbol	Derivation	Comments
RIKEN	Japonium	Jp	Japan - country of group claimants
RIKEN	Rikenium	Rk	RIKEN - institute of group claimants	possibly against the rules

Disallowed Names

According to IUPAC rules, names used for previous elements that have ultimately not been adopted are not allowed to be proposed for future use. The table below summarises those names which are probably not allowed to be proposed by the claimant laboratories under the rules.

Group Claim Affected	Disallowed Name	Disallowed Symbol	Reason
RIKEN	Nipponium	Np	Used for claimed discovery of element 43
Dubna	Russium	Rs	Used for claimed discovery of element 43

Plausible Names

Many speculative names appear in popular literature. The table below lists these names in the case where they obey IUPAC rules and are plausible with regard to the claimant laboratories. Rumoured suggestions (*) linked to the claimant laboratories are also included.

Group Link	Suggested Name	Suggested Synbol	Derivation	Comments
RIKEN	Nihonium *	Nh	Nihon - Japanese for Japan
Dubna	Becquerelium *	Bq	Henri Becquerel - discoverer of radioactivity	Dubna team suggested the name for element 110

History

Synthesis of Isotopes by Hot Fusion

In June 2006, the Dubna-Livermore team synthesised ununtrium directly in the "warm" fusion reaction between neptunium-237 and calcium-48 nuclei. Two atoms of ²⁸²Uut were detected.

$\,_{20}^{48}\mathrm {Ca} +\,_{93}^{237}\mathrm {Np} \to \,_{113}^{285}\mathrm {Uut} ^{*}\to \,_{113}^{282}\mathrm {Uut} +3\,_{0}^{1}\mathrm {n}$

Yields of Isotopes

Cold Fusion

The table below provides cross-sections and excitation energies for cold fusion reactions producing ununtrium isotopes directly. Data in bold represents maxima derived from excitation function measurements. + represents an observed exit channel.

Projectile	Target	CN	1n	2n	3n
70Zn	209Bi	279Uut	31 fb

Hot Fusion

The table below provides cross-sections and excitation energies for hot fusion reactions producing ununtrium isotopes directly. Data in bold represents maxima derived from excitation function measurements. + represents an observed exit channel.

Projectile	Target	CN	3n	4n	5n
48Ca	237Np	285Uut	0.9 pb , 39.1 MeV

See also

• Isotopes of ununtrium
• Island of stability

External links

• WebElements.com - Uut
• Uut and Uup Add Their Atomic Mass to Periodic Table
• Apsidium - Ununtrium
• Discovery of Elements 113 and 115
• Superheavy elements