Actinide
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The actinide or actinoid series encompasses at least the 14 metallic chemical elements in the 5f series, with atomic numbers from 89 to 102, actinium through to nobelium. Number 103, lawrencium, is al
Enrico Fermi suggested the existence of transuranium elements in 1934.
Glenn T. Seaborg and his group at the University of California at Berkeley synthesized Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and element 106, which was later named seaborgium in his honor while he was still living. They also synthesized more than a hundred actinide isotopes.
Monazite: a major thorium mineral
A pellet of 238PuO2 to be used in a radioisotope thermoelectric generator for either the Cassini or Galileo mission. The pellet produces 62 watts of heat and glows because of the heat generated by the radioactive decay (primarily α). Photo is taken after insulating the pellet under a graphite blanket for minutes and removing the blanket.
Lanthanide
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A lanthanide is any of the 15 metallic chemical elements with atomic numbers 57–71, from lanthanum through lutetium. In the periodic table, the first fourteen fill the 4f orbitals. Lutetium is also of
Actinide
…in the ground state many have anomalous configurations involving the filling of the 6d shell due to interelectronic repulsion. In comparison with the lanthanides, also mostly f-block elements, the actinides show much more variable valence. They all have very large atomic and ionic radii and exhibit an unusually…
Lanthanide oxides: clockwise from top center: praseodymium, cerium, lanthanum, neodymium, samarium and gadolinium
Samples of lanthanide elements (excluding promethium)