|
transuranium elements
transuranium elements in chemistry, radioactive elements with atomic numbers greater than that of uranium (at. no. 92). All the transuranium elements of the actinide series were discovered as synthetic radioactive isotopes at the Univ. of California at Berkeley or at Argonne National Laboratory...
Read more
|
|
transactinide elements
transactinide elements , in chemistry, elements with atomic numbers greater than that of lawrencium (at. no. 103), the last member of the actinide series. See transuranium elements .
...
Read more
|
|
Glenn Theodore Seaborg
Glenn Theodore Seaborg , 1912-99, American chemist, b. Ishpeming, Mich., grad. Univ. of California at Los Angeles, 1934, Ph.D. Univ. of California at Berkeley, 1937. In 1939, he began teaching at Berkeley, where he became professor of chemistry (1945) and chancellor of the university (1958). During ...
Read more
|
|
Edwin Mattison McMillan
Edwin Mattison McMillan 1907-91, American physicist, b. Redondo Beach, Calif., grad. California Institute of Technology, 1928, Ph.D. Princeton, 1932. On the faculty of the Univ. of California from 1932, he was appointed professor of physics in 1946 and director of the Lawrence Radiation Laboratory ...
Read more
|
|
fermium
fermium [for Enrico Fermi ], artificially produced radioactive chemical element; symbol Fm; at. no. 100; mass no. of most stable isotope 257; m.p. 1,527°C; b.p. and sp. gr. unknown; valence +2, +3. Fermium is a member of Group 3 of the periodic table . The physical properties of fermium are l...
Read more
|
|
hassium
hassium , artificially produced radioactive chemical element; symbol Hs; at. no. 108; mass number of most stable isotope 265; m.p., b.p., sp. gr., and valence unknown. Situated in Group 8 of the periodic table , it is expected to have properties similar to those of osmium .
In 1984 a German r...
Read more
|
|
lawrencium
lawrencium artificially produced radioactive chemical element; symbol Lr; at. no. 103; mass number of most stable isotope 262; m.p. about 1,627°C; b.p. and sp. gr. unknown; valence +3. Lawrencium is the last member of the actinide series of elements found in Group 3 of the periodic table . L...
Read more
|
|
mendelevium
mendelevium , artificially produced radioactive chemical element; symbol Md; at. no. 101; mass no. of most stable isotope 258; m.p. 827°C; b.p. and sp. gr. unknown; valence +1, +2, +3. Mendelevium is a metal of the actinide series in Group 3 of the periodic table . The ninth transuranium ele...
Read more
|
|
neptunium
neptunium , radioactive chemical element; symbol Np; at. no. 93; at. wt. 237.0482; m.p. about 640°C; b.p. 3,902°C (estimated); sp. gr. 20.25 at 20°C; valence +3, +4, +5, or +6. Neptunium is a ductile, silvery radioactive metal. It is a member of the actinide series in Group 3 of the p...
Read more
|
|
nobelium
nobelium , artificially produced radioactive chemical element; symbol No; at. no. 102; mass no. of most stable isotope 259; m.p. 827°C; b.p. and density unknown; valence +2, +3. It is a metal of the actinide series in Group 3 of the periodic table . Nobelium was the 10th transuranium element...
Read more
|