Mendelevium

   Scientists had worked for many years to devise a universal system for classifying the elements, but with limited success. Dimitri Ivanovich Mendeleev, or Mendeleyev (1834-1907), inaugurated a system called the Periodic Law of the Chemical Elements which arranged the elements in order of increasing atomic weight so that they could be arranged in tables of vertical columns. Not only were scientists now able to check disputed data about known elements, but this system showed a number of spaces into which no known element would fit. This indicated to Mendeleev that certain elements had not yet been discovered. The system was remarkable in that it was able to predict with great accuracy both the atomic weights and general properties of elements that were later discovered. Born in Siberia and educated at the University of St. P rsburg, Mendeleev became the director of weights and measures for the czar and introduced the metric system into his country. In 1955, four eminent American scientists—Glenn Seaborg, Bernard Harvey, Gregory Choppin, and S. G. Thompson—discovered an artificially produced radioactive element, 101, and named it mendelevium for Dimitri Mendeleev. Mendelevium is formed in the laboratory by bombarding the element einsteinium with alpha particles.