Russia Gallery

Mendeleyevs periodic table, 1869

Mendeleyev's periodic table, 1869. Mendeleyev's periodic table of 1869. This is the first version of the periodic table drawn up by the Russian chemist Dmitri Ivanovich Mendeleyev (1834-1907). He left gaps in the table for new elements, that were indeed later discovered, vindicating his theory. This version has the elements listed using chemical symbols, and ordered by atomic weight, but the fully correct chemical arrangement has not yet emerged. The final version (1871) had the elements arranged in the familiar vertical columns or groups. This version is dated (lower left) to 17 February 1869, and Mendeleyev's name is at top. This manuscript is from the Mendeleyev museum. Photographed in St Petersburg, Russia. See also H413/297

© RIA NOVOSTI/SCIENCE PHOTO LIBRARY

Mao Zedong meeting Che Guevara

Chinese Communist leader, Mao Zedong (1893-1976), also known as Chairman Mao. Seen here meeting and greeting Ernesto "Che" Guevara (1928-1967), the Argentinian Marxist revolutionary, physician, writer, guerrilla leader, diplomat, military theorist, and major figure in the Cuban Revolution, who had taken a pro-Chinese stance on a split between China and Soviet Russia

© Mary Evans Picture Library 2015 - https://copyrighthub.org/s0/hub1/creation/maryevans/MaryEvansPictureID/10472052

Carl Sagan, US astronomer

Carl Edward Sagan (1934-1996), US astronomer and astrochemist. Sagan was a consultant and adviser to NASA, and worked on the Apollo mission, as well as the Mariner, Viking, Voyager, and Galileo space probes and planetary exploration programs. He proposed theories to explain the high temperature of Venus, the seasonal changes on Mars, and the reddish haze of Titan. He was a prominent sceptic and populariser of science, writing many books on the subject. He also campaigned for nuclear disarmament, and spoke at the conference of the International Physicians for the Prevention of Nuclear War in Moscow in the summer of 1987. Photographed in 1987, in Moscow, Russia

© RIA NOVOSTI/SCIENCE PHOTO LIBRARY