Write about Hassium atom.

     

Hassium is a chemical element with the symbol Hs and the atomic number 108.  Hassium is highly radioactive;  its most stable known isotopes have half-lives of approximately ten seconds.  One of its isotopes, 270Hs, has magic numbers of both protons and neutrons for deformed nuclei, which gives it greater stability against spontaneous fission.  Hassium is a super heavy element;  it has been produced in a laboratory only in very small quantities by fusing heavy nuclei with lighter ones.  Natural occurrences of the element have been hypothesized but never found.  

     In the periodic table of elements, hassium is a transactinide element, a member of the 7th period and group 8;  it is thus the sixth member of the 6d series of transition metals.  Chemistry experiments have confirmed that hassium behaves as the heavier homologue to osmium, reacting readily with oxygen to form a volatile tetroxide.  The chemical properties of hassium have been only partly characterized, but they compare well with the chemistry of the other group 8 elements.  

     The principal innovation that led to the discovery of hassium was the technique of cold fusion, in which the fused nuclei did not differ by mass as much as in earlier techniques.  It relied on greater stability of terget nuclei, which in turn decreased excitation energy.  This decreased the number of neutron ejections during synthesis, creating heavier, more stable resulting nuclei.  The technique was first tested at the Joint institute for Nuclear Research (JINR) in Dubna, Moscow Oblast, Russian SFSR, Soviet Union, in 1974.  JINR used this technique to attempt synthesis of element 108 in 1978, in 1983, and in 1984; the latter experiment resulted in a claim that element 108 had been produced.  Later in 1984,  a synthesis claim followed from the gesellschaft fur Schwerioneforschung(GSI) in Darmstadt, Hesse, West Germany.