Mendeleev's law

Mendeleyev, Dmitry Ivanovich (1834–1907), Russian chemist. Mendeleyev made a fundamental contribution to chemistry by proving that all chemical elements are related members of a single ordered system. He was a professor of chemistry at St. Petersburg, and in his later years he served as director of his government's bureau of weights and measures. In 1869 he devised his original version of a periodic table in which all known elements are arranged according to their atomic weights. In his improved table of 1871 he left gaps for elements not yet discovered but which had predictable properties. He also formulated a periodic law stating that the chemical properties of the elements are periodic functions of their atomic weights. His periodic table became the framework for a great part of chemical theory and proved to be highly useful in the interpretation of the processes of radioactive decay. The table also served to unify much of modern physics. The radioactive element mendelevium was named in his honor when it was first produced by scientists in 1955.