Bohrium Unnilseptium

SYMBOL Bh (Uns) PERIOD 7 SERIES NAME Transactinide ATOMIC NO 107 

ATOMIC MASS 272 amu VALENCE None OXIDATION STATE Unknown NATURAL STATE Solid 

ORIGIN OF NAME Named after the scientist Niels Bohr. 

ISOTOPES There are a total of 10 isotopes of unnilseptium (bohrium). Not all their half-lives are known. However, the ones that are known range from 8.0 milliseconds to 9.8 seconds for Bh-272, which is the most stable Isotope of bohrium and which decays Into dubnlum-268 through alpha decay. Only one Isotope, Uns-261, has a decay mode that Involves both alpha decay and spontaneous fission. All the others decay by alpha emission. 

Energy Levels/Shells/Electrons Orbltals/Electrons 

---

Bohrium (Unnilseptium) Bh or Uns 1981 (Darmstadt, Germany) Peter Armbruster and Gottfried Munzenberg (both German) 346... 

Unnilseptium, or bohrium, is artificially produced one atom at a time in particle accelerators. In 1976 Russian scientists at the nuclear research laboratories at Dubna synthesized element 107, which was named unnilseptium by lUPAC. Only a few atoms of element 107 were produced by what is called the cold fusion process wherein atoms of one element are slammed into atoms of a different element and their masses combine to form atoms of a new heavier element. Researchers did this by bombarding bismuth-204 with heavy ions of chromium-54 in a cyclotron. The reaction follows Bi-209 + Cr-54 + neutrons = (fuse to form) Uns-262 + an alpha decay chain. 

The two scientists then traced the very short decay sequence of the three Une-266 atoms as they decayed into element 107 (unnilseptium or bohrium) and element number 105 (unnil-pentium or dubnium). The decay sequence is as follows ... 

---