The Elements (07Nov00):

unnilhexium
Symbol:
Atomic number: 106
Atomic weight: (263)
Half-life of 0.9 +/- 0.2 s. Discovered by the Joint Institute for
Nuclear
Research at Dubna (U.S.S.R.) in June of 1974. Its existence was
confirmed
by the Lawrence Berkeley Laboratory and Livermore National Laboratory in
September of 1974.