Dmitri Mendeleev was a Russian chemist born in 1834 who invented the periodic table. He organized the known elements into a table arranged by atomic mass, with elements in the same column having similar chemical properties. His periodic table predicted elements yet to be discovered. Mendeleev had a difficult childhood with his family facing poverty after his father went blind and his mother died of tuberculosis. He graduated from university in 1855 and became a professor, publishing works on chemistry and inventing the periodic table in 1869 which became widely accepted for its predictive power. Mendeleev made many contributions to chemistry and received honors before his death in 1907.