Artificial radioactive element m.p. 994±4 ºC; 1821±7 ºF b.p. 2607 ºC; 4725 ºF density 13.67 g/cc; 853.39 pound/cubic foot	memory peg
	1944-45 Glenn T. Seaborg and co-workers, Chicago, Ill., USA
	America, continent

First prepared in 1944-45 by Glenn T. Seaborg (1912-1999), Ralph A. James, Leon O. (Tom) Morgan, and Albert Ghiorso at the Metallurgical Laboratory of the University of Chicago by irradation of Plutonium with neutrons.

They researchers prepared the elements #95 and #96 while Plutonium was being produced in industrial proportions, in Hanford, to be used in nuclear weapons. Their labor lasted more than one year, being the difficulties so big that one of them suggested that the newly found elements should be called Pandemonium and Delirium. In spite of this, the elements were given the names Americium and Curium. About the naming, Glenn Seaborg wrote in 1994:

"Thus element 95 would be chemically similar to the lanthanide element europium (63) and element 96 would be chemically similar to gadolinium (64). Using this concept, in 1944 and 1945 we synthesized and chemically identified elements 95 and 96, by analogy with their rare earth homologues, europium (element 63) and gadolinium (element 64). The new elements were subsequently named americium (95) and curium (96)." (note)

At a meeting of the Heavy Isotopes Group at the Metallurgical Laboratory on March 5, 1946, I suggested that 95 and 96 be named "americium" and "curium" by analogy to the naming of their lanthanide homologs "europium" and "gadolinium." It was also pointed out that the +2 state of element 96 would be "cur-ious," but I replied that this oxidation state was not expected to exist.

The element is named after America, special the United States of America. The continent is named after Amerigo Vespucci, who made some voyages to the New World, several years after the discovery by Christopher Columbus. Vespucci's letters describing the New World were published and made the continent known to European scholars. The cosmographer Martin Waldseemüller proposed therefor the name America for the new world (1506).
Vespucci's first name "Amerigo" is the early-medieval Italian form of the German name "Heinrich" (earlier: "Heimerich" from: Old German heim = "home, estate" + Old German ric = "force, power, government").

John and Gordon Marks suggested in 1994 the name Columbium (Cb) after the New World. The Marks brothers found the old names ugly and confusing. They offered alternative names that are equivalent contemporary (at the time and place of discovery) metaphors, both more euphonious and more memorable. For Americium they suggested Columbium with the argument that Europium is named after Europe. Personally, I don't understand what they have against Americium (note).

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Map of America or the New World from the Epitome, published by Filips Galle in Antwerp, 1588 (this copy from the edition by J.B. Vrients, 1602).

False transuranic elements (#93-97)

Element #95 has got in 1934-38 the preliminary name Eka-Iridium by Otto Hahn, Lise Meitner and Fritz Strassmann in Germany, who thought they had found traces of several transuranium elements. In December of 1938, Hahn and Strassman found out that these radioactivities were not due to transuranium elements but were due to fission products. According to the Periodic Table of that time, without the Actinide series, element #95 is below Iridium (#77). According to the present Table, Eka-Iridium would be #109.

Further reading:

• Mary Elvira Weeks, Discovery of the Elements, comp. rev. by Heny M. Leicester (Easton, Pa.: Journal of Chemical Education, 1968), pp. 846-848.
• Glenn T. Seaborg, Ralph A. James, & Leon O. Morgan, The New Element Americium (Atomic Number 95). DOE-report. January 1948. (Full text in PDF available on-line).
• Earl K. Hyde & Glenn T. Seaborg, Transurane : Teil A 1, I: Die Elemente. Gmelins Handbuch der anorganische Chemie, Ergänzungswerk zur 8. Aufl.; Band 7a. Weinheim/Bergstrasse: Chemie, 1973.
• Glenn T. Seaborg, "My Romance with the Transuranium Elements" R&D Innovator 3, 12 (Dec. 1994). (on-line)