Science
Hassium 270
An interesting result from the realm of experimental nuclear physics was announced recently by a team of 24 scientists from 10 research institutions, including the Technical University of Munich (TUM) and the Institute for Heavy-Ion Research (GSI) as well as institutions in Russia, the U.S., Switzerland, Japan, China, and Poland. The group is engaged in "transactinide chemistry", a fancy term for research into the chemical properties of super-heavy elements [the transactinide's are those elements with atomic number greater than Lawrencium, 103Lr (atomic number Z=103), the last element of the actinide series].As is the case with all elements with atomic number larger than Plutonium (Z=94), 270Hassium (Z=108) is not naturally occuring and is created by colliding two lighter nuclei. In the TUM experiment, a high energy beam of 26Mg (atomic mass number A=26) atoms are collided with a stationary target of 248Cm to form 270Hs (with four neutrons as byproducts). Pretty standard fare for super-heavy nuclei, though the researchers exploited a known feature of 269Hs which forms tetroxides when exposed to oxygen allowing for easier analysis of nuclear and chemical properties in a chromatographic detector.
And the result was to peg the lifetime of 270Hs at 30 seconds - an eternity when compared to most super-heavy nuclei which are deformed and decay in milliseconds. The fact that 270Hs was found to be 'long lived' confirmed theoretical expectations that the element would be near an island of stability. These 'islands' refer to elements having a certain combination of neutrons and protons (filled 'shells') which are energetically favorable and result in a nucleus less prone to decay through fission or other routes. 270Hs is close to the island expected to have 184 neutrons and 114 protons and theoretical calculations indicated 270Hs had sufficient closed subshells to give relative stability and long life. Elements on and near the island will also have spherical nuclei unlike their deformed super-heavy brethren. Unfortunately, the experimentalists haven't yet figured out a way to combine lighter elements to create one of the elements at the center of this island, such as ununquadium-298, unbinilium-304 and unbihexium-310 (all with 184 neutrons and proton numbers 114, 120 and 126). Unbihexium-310 is predicted to be the most stable as both the number of protons (126) and neutrons (184) are magic (closed shells), hence this element would be 'doubly magic' and very unlikely to decay. Note the funny element names are 'systematic element names' - temporary placeholders formed by an internationally approved methodology and used until the element is actually created for real. Once confirmed, an official name is assigned.
