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Encyclopediamendeleviummendelevium (mendulāv'ēum) [key], 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 element to be discovered, it is named for the Russian chemist Dmitri Ivanovich Mendeleev. The symbol Mv was used at first, but it was changed to Md in 1963. Sixteen isotopes of mendelevium are known. Mendelevium-256 (half-life about 76 min) was the first isotope produced; it was detected in 1955 by Albert Ghiorso, Bernard G. Harvey, Gregory R. Choppin, Stanley G. Thompson, and Glenn T. Seaborg, who produced it one atom at a time by bombarding einsteinium-253 with alpha particles in a cyclotron at the Univ. of California at Berkeley. This technique of producing and detecting single atoms has become the standard for the discovery of the elements beyond mendelevium in the periodic table. Little is known of the properties of this element, since its isotopes are unstable and difficult to produce. Mendelevium-258 (the most stable isotope) has a half-life of 52 days; its synthesis (by bombarding einsteinium-255 with alpha particles) may make possible studies of the physical and chemical properties of the element. The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2007, Columbia University Press. All rights reserved. More on mendelevium from Infoplease:
- Periodic Table of the Elements: Mendelevium - Periodic Table of the Elements: Mendelevium Atomic Number: 101 Atomic Symbol: Md Mendelevium Atomic ...
- Chemical Elements Table - Chemical Elements Table See the interactive periodic table. Element Sym- bol Atomic no. Atomic wt. ...
- Md - Md Md, symbol for the element mendelevium.
- Mv - Mv Mv, former symbol of the element mendelevium, now Md.
- einsteinium - einsteinium einsteinium [for Albert Einstein], artificially produced radioactive chemical element; ...
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