Dimitri Ivanovich Mendeleev
Ideas – Elements placed according to the value of their atomic weights present a clear periodicity of properties. Biography The youngest, of at least, fourteen children, Dimitri Ivanovitch Mendeleev was born at Tobolsk, Siberia, on 7th February, 1834. His father, Ivan, was the director of the local gymnasium, and his mother, Marya, came from