mendelevium
mendelevium (men*de*lē"vē*u/m) , adjective
[From Dmitri Mendeleyev, discoverer of the periodic law.]
(Chemistry) an unstable radioactive element discovered in 1955 and produced artificially only in very small quantities; symbol Md (also Mv). It is a transuranic element with atomic number 101. Isotopes 255, 256, 257, and 258 have been prepared. Md258, the longest-lived, has a half-life of two months. — HCP61