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Like all synthetic transuranic elements, isotopes of einsteinium are very radioactive and are considered highly dangerous to health on ingestion. [3]
Its chemistry is typical of the late actinides, with a preponderance of the +3 oxidation state; the +2 oxidation state is also available, particularly in solids. The high radioactivity of einsteinium-253 produces a visible glow and rapidly damages its crystalline metal lattice, with published heat of about 1000 watts per gram. Difficulty in studying its properties is because of einsteinium-253's decay to berkelium-249 and then californium-249 at a speed of about 3% per day. The isotope of einsteinium with the longest half-life, einsteinium-252 (half-life 471.7 days) would be more acceptable for investigation of physical attributes, but it has proven a lot more difficult to make and is available only in minute quantities, and not in bulk. [1] Einsteinium is the component with the greatest atomic number that has been observed in macroscopic amounts in its pure form, which was the common short-lived isotope einsteinium-253. [2]
Einsteinium is a member of the actinide series and it's the seventh transuranic element. It's named to honor Albert Einstein.
). [5] Larger quantities of radioactive material were later isolated from coral debris of the atoll, which were delivered to the U.S.[4] The separation of suspected new components was completed in the presence of a citric acid/ammonium buffer solution in a weakly acidic medium (pH ≈ 3.5), using ion exchange at elevated temperatures; fewer than 200 atoms of einsteinium were recovered at the end. [6] Nevertheless, element 99 (einsteinium), namely its 253Es isotope, could be detected via its feature high performance alpha decay at 6.6 MeV. Such multiple neutron absorption was made possible by the high neutron flux density during the detonation, so that newly generated heavy isotopes had lots of available neutrons to absorb before they could disintegrate into lighter elements. Neutron capture initially increased the mass number without changing the atomic number of the nuclide, along with the concomitant beta-decays resulted in a slow increase in the atomic number:[4]
Some 238U atoms, however, could absorb two additional neutrons (for a total of 17), resulting in 255Es, in addition to in the 255Fm isotope of another new element, fermium. [7] The discovery of the new elements and the associated new data on multiple neutron capture were originally kept secret on the orders of the U.S. military until 1955 because of Cold War tensions and competition with Soviet Union in nuclear technologies. [4][8][9] However, the rapid capture of so many neutrons would supply needed direct experimental confirmation of the so-called r-process multiple neutron absorption required to explain the cosmic nucleosynthesis (production) of certain heavy chemical elements (heavier than nickel) in supernova explosions, prior beta decay. Such a process is needed to explain the existence of several stable elements in the universe. [10]
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Indicated that still more neutrons might have been seized by the uranium nuclei, thereby producing new elements heavier than californium. [4]
Ghiorso and co-workers examined filter papers which were flown through the burst cloud on planes (the same sampling technique that was used to discover 244
Einsteinium was discovered as a part of the debris of the first hydrogen bomb explosion in 1952. Its most frequent isotope einsteinium-253 (half-life 20.47 days) is produced artificially from decay of californium-253 in a few committed hemorrhagic atomic reactors with a total return on the order of one milligram per year. The reactor synthesis is followed by a complex process of separating einsteinium-253 from other actinides and products of the decay. Other isotopes are synthesized in various labs, but in much smaller amounts, by bombarding heavy actinide elements with light ions. Owing to the small quantities of generated einsteinium and the brief half-life of its most easily produced isotope, there are now almost no practical applications for it outside fundamental scientific research. In particular, einsteinium was used to synthesize, for the first time, 17 atoms of the new element mendelevium in 1955.
displaystyle ce ^252_98Cf ->[ce (n,gamma)] ^253_98Cf ->[beta^-][17.81 ce d] ^253_99Es ->[ce (n,gamma)] ^254_99Es ->[beta^-] ^254_100Fm
Einsteinium was initially identified in December 1952 by Albert Ghiorso and co-workers at the University of California, Berkeley in collaboration with the Argonne and Los Alamos National Laboratories, in the fallout from the Ivy Mike nuclear test. [4] Initial examination of the debris from the explosion had revealed the production of a new isotope of plutonium, 244
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In their discovery of the elements 99 and 100, the American teams had collaborated with a group in the Nobel Institute for Physics, Stockholm, click here Sweden. In late 1953 -- early 1954, the Swedish team succeeded in the synthesis of light isotopes of element 100, in particular 250Fm, by bombarding uranium with oxygen nuclei. These results were also published in 1954. [19] Nevertheless, the priority of the Berkeley team was generally recognized, as its publications preceded the Swedish post, and they had been based on the previously undisclosed results of this 1952 thermonuclear explosion; hence the Berkeley team was awarded the liberty to name the new elements. As the campaign which had led to the design of Ivy Mike was codenamed Project PANDA,[20] component 99 was jokingly nicknamed"Pandamonium"[21] but the official titles suggested by the Berkeley group derived from two prominent scientists, Albert Einstein and Enrico Fermi:"We propose for the title for the element with the atomic number 99, einsteinium (symbol E) after Albert Einstein and for the title for the element with atomic number 100, fermium (symbol Fm), after Enrico Fermi." [8] Both Einstein and Fermi died between the time the names were initially proposed and if they were announced. The discovery of these new elements was declared by Albert Ghiorso in the first Geneva Atomic Conference held on 8--20 August 1955. [4] The symbol for einsteinium was initially given as"E" and later changed to"Es" by IUPAC.
These results were published in a number of posts in 1954 with the disclaimer that these weren't the initial studies that had been completed on the elements. [12][13][14][15][16] The Berkeley team also reported some results on the chemical properties of einsteinium and fermium. [17][18] The Ivy Mike results were declassified and published in 1955. [8]
displaystyle ce ^238_92U ->[ce +15n][6 beta^-] ^253_98Cf ->[beta^-] ^253_99Es
At the time, the multiple neutron absorption has been thought to be an extremely rare process, but the identification of 244
Meanwhile, the isotopes of element 99 (as well as of new element 100, fermium) were created in the Berkeley and Argonne labs, in a nuclear reaction between nitrogen-14 and uranium-238,[11] and later by intense neutron irradiation of plutonium or californium: