MD

Md may refer to several different things. In science, Md is the symbol for mendelevium, the chemical element with atomic number 101. Mendelevium is a synthetic, highly radioactive actinide. It was first synthesized in 1955 by a team at Lawrence Berkeley National Laboratory, led by Glenn T. Seaborg and Albert Ghiorso, by bombarding einsteinium with alpha particles. The element is named after Dmitri Mendeleev, the Russian chemist who created the periodic table. All of its isotopes are radioactive and have short half-lives; mendelevium has been produced only in extremely small quantities and primarily for basic research into the properties of heavy elements.

In geography, Md is used as an abbreviation for the U.S. state of Maryland, whose postal code is MD. Maryland lies in the Mid-Atlantic region and was one of the original thirteen colonies.

In medicine, Md stands for Doctor of Medicine, a professional degree. The capitalization varies by usage: MD is the common form in the United States for the degree or credential, while Md is sometimes seen in other contexts or in older texts.