Mendelevium (Md), synthetic chemical element of the actinoid series of the periodic table, atomic number 101. It was the first element to be synthesized and discovered a few atoms at a time. Not occurring in nature, mendelevium (as the isotope mendelevium-256) was discovered (1955) by American chemists Albert Ghiorso, Bernard G. Harvey, Gregory R. Choppin, Stanley G. Thompson, and Glenn T. Seaborg at the University of California, Berkeley, as a product resulting from the helium-ion (alpha-particle) bombardment of a minute quantity (about a billion atoms) of einsteinium-253 (atomic number 99). The element was named after Russian chemist Dmitry Mendeleyev. Continue reading from Encyclopedia Britannica
Seventeen atoms of mendelevium were made in 1955 by Albert Ghiorso, Bernard Harvey, Gregory Chopin, Stanley Thompson, and Glenn Seaborg. They were produced during an all-night experiment using the cyclotron at Berkeley, California. In this, a sample of einsteinium-253 was bombarded with alpha-particles (helium nuclei) and mendelevium-256 was detected. This had a half-life of around 78 minutes. Further experiments yielded several thousand atoms of mendelevium, and today it is possible to produce millions of them. The longest lived isotope is mendelevium-260 which has a half-life of 28 days. Continue reading from Royal Society of Chemistry
Only small quantities of mendelevium have ever been produced, so it has no commercial uses. It is used only for scientific research. The isotope 256Md has been helpful in understanding some of the chemical properties of mendelevium in aqueous solution. Mendelevium has 14 recognized isotopes. The most stable one is 258Md, which has a half-life of about 51.5 days. As is characteristic of actinide elements, mendelevium possesses a III oxidation state. Experiments indicate that it also possesses a moderately stable II oxidation state. Continue reading from Live Science
