Meitnerium is a synthetic chemical element; it has symbol Mt and atomic number 109. It is an extremely radioactive synthetic element. The most stable known isotope, meitnerium-278, has a half-life of
Meitnerium was named after the physicist Lise Meitner, one of the discoverers of nuclear fission.
Hassium is a synthetic chemical element; it has symbol Hs and atomic number 108. It is highly radioactive: its most stable known isotopes have half-lives of about ten seconds. One of its isotopes, 270
Meitnerium
…as the yields for heavier elements are predicted to be smaller than those for lighter elements; some of the separation techniques used for bohrium and hassium could be reused. However, the experimental chemistry of meitnerium has not received as much attention as that of the heavier elements from copernicium…
GSI's linear particle accelerator UNILAC, where hassium was discovered and where its chemistry was first observed
Energy levels of outermost orbitals of hassium and osmium atoms in electronvolts, with and without taking relativistic effects into account. Note the lack of spin–orbit splitting (and thus the lack of distinction between d3/2 and d5/2 orbitals) in nonrelativistic calculations.