Dmitri Ivanovich Mendeleev, born February 8, 1834, was a Russian chemist. He is famous for his formulation (1869) of the periodic law and the invention of the periodic table, a classification of the elements; with Lothar Meyer, who had independently reached similar conclusions, he was awarded the Davy medal in 1882. From his remarkable table Mendeleev predicted the properties of elements then unknown; three of these (gallium, scandium, and germanium) were later discovered.
Julius Robert Oppenheimer (April 22, 1904 – February 18, 1967) was an American theoretical physicist and professor of physics at the University of California, Berkeley. Along with Enrico Fermi, he is often called the "father of the atomic bomb" for his role in the Manhattan Project, the World War II project that developed the first nuclear weapons.