Wading Towards The Shores Of The Island Of Stability - Ununbium 112

It's just about official:

BERLIN (Reuters) – A new, superheavy chemical element numbered 112 will soon be officially included in the periodic table, German researchers said.

A team in the southwest German city of Darmstadt first produced 112 in 1996 by firing charged zinc atoms through a 120-meter-long particle accelerator to hit a lead target.

...The International Union of Pure and Applied Chemistry (IUPAC), confirmed the discovery of 112 by the team led by Sigurd Hofmann at the Helmholtz Center. IUPAC has asked for an official name for the element to be submitted.

...The atomic number 112 refers to the sum of the atomic numbers of zinc, which has 30, and lead, which has 82. Atomic numbers denote how many protons are found in the atom's nucleus.

According to Wikipedia, the confirmation of ununbium's creation was quite complicated:

The IUPAC/IUPAP Joint Working Party (JWP) assessed the claim of discovery by the GSI team in 2001 and 2003. In both cases, they found that there was insufficient evidence to support their claim. This was primarily related to the contradicting decay data for the known isotope 261Rf. However, between 2001-2005, the GSI team studied the reaction 248Cm(26Mg,5n)269Hs, and were able to confirm the decay data for 269Hs and 261Rf. It was found that the existing data on 261Rf was for a metastable isomer, namely 261mRf.

In May 2009, the JWP reported on the claims of discovery of element 112 again and officially recognised the GSI team as the discoverers of element 112. This decision was based on recent confirmation of the decay properties of daughter nuclei as well as the confirmatory experiments at RIKEN.

The lifetime of 285Uub is listed as 29 seconds, which seems like forever in heavy-element land. Are we approaching the island of stability?:

The idea of the island of stability was first proposed by Glenn T. Seaborg. The hypothesis is that the atomic nucleus is built up in "shells" in a manner similar to the electron shells in atoms. In both cases shells are just groups of quantum energy levels that are relatively close to each other. Energy levels from quantum states in two different shells will be separated by a relatively large energy gap. So when the number of neutrons and protons completely fill the energy levels of a given shell in the nucleus, the binding energy per nucleon will reach a local minimum and thus that particular configuration will have a longer lifetime than nearby isotopes that do not have filled shells.

A filled shell would have "magic numbers" of neutrons and protons. One possible magic number of neutrons is 184, and some possible matching proton numbers are 114, 120 and 126 — which would mean that the most stable possible isotopes would be ununquadium-298, unbinilium-304 and unbihexium-310. Of particular note is Ubh-310, which would be "doubly magic" (both its proton number of 126 and neutron number of 184 are thought to be magic) and thus the most likely to have a very long half-life. (The next lighter doubly-magic nucleus is lead-208, the heaviest stable nucleus and most stable heavy metal.) None of these superheavy isotopes has yet been produced, but isotopes of elements in the range between 110 through 114 have been found to decay slower than isotopes of nuclei nearby in the periodic table.

...The half lives of elements in the island are uncertain due to the small number of atoms manufactured and studied to date. Many physicists think they are relatively short, on the order of minutes, hours, or perhaps days. However, some theoretical calculations indicate that their half lives may be long (some calculations put it on the order of 109 years). It is possible that these elements could have unusual chemical properties, and, if long lived enough, various applications (such as targets in nuclear physics and neutron sources). However, the isotopes of several of these elements still have too few neutrons to be stable. The island of stability still has not been reached, since the island's "shores" are more neutron rich than nuclides that have been experimentally produced.

...Manufacturing nuclei in the island of stability may be very difficult, because the nuclei available as starting materials do not deliver the necessary sum of neutrons. So for the synthesis of isotope 298 of element 114 by using plutonium and calcium, one would require an isotope of plutonium and one of calcium, which have together a sum of at least 298 nucleons (more is better, because at the nuclei reaction some neutrons are emitted). This would require, for example, the use of calcium-50 and plutonium-248 for the synthesis of element 114 . However these isotopes (and heavier calcium and plutonium isotopes) are not available in weighable quantities. This is also the case for other target-projectile combinations.

...“ We search for the island of stability because, like Mount Everest, it is there. But, as with Everest, there is profound emotion, too, infusing the scientific search to test a hypothesis. The quest for the magic island shows us that science is far from being coldness and calculation, as many people imagine, but is shot through with passion, longing and romance." -- Oliver Sacks