n a radioactive transuranic element synthesized by bombarding einsteinium with alpha particles (Md is the current symbol for mendelevium but Mv was formerly the symbol)
Even more important, mendelevium stays around long enough to make a good target for high-velocity particle accelerators.
Berkeley's Hilac will be used chiefly for transmuting elements, especially for attempting to create new elements heavier than mendelevium (element 101).