Dimitri Mendeleev, a Russian chemist who in 1869 wrote out the known elements (of which there were 63 at the time) on cards and then arranged them in columns and rows according to their chemical and physical properties, is considered the father of the Periodic Table. In celebration of the 150th anniversary of this pivotal moment in science, the UN has proclaimed 2019 the International year of the Periodic Table. UNESCO announced in their press release, “The Periodic Table of Chemical Elements is more than just a guide or catalogue of the entire known atoms in the universe; it is essentially a window on the universe, helping to expand our understanding of the world around us.”
But the periodic table did not begin with Mendeleev. Decades before, chemist John Dalton tried to create a table as well as some rather interesting symbols for the elements (they didn’t catch on). And just a few years before Mendeleev sat down with his deck of homemade cards, John Newlands also created a table sorting the elements by their properties.
Newly announced by the IUPAC in 2016, four more elements were added to the table. The Heavy Element Group lead by alumna nuclear chemist Dawn Shaughnessy (B.S. Chem, '93; Ph.D. Nuclear Chem, '00) at Lawrence Livermore National Laboratory worked with teams of scientists in Russia and Japan on the elements discovery. The four elements are officially named Nihonium, Moscovium, Tennessine, and Oganesson. The elements have been given the atomic numbers 113, 115, 117, and 118 finishing off the seventh row on the Table.
UC Berkeley faculty have a substantial history as well of element discovery. In the 1930s, physicist Ernest Lawrence helped establish the Radiation Laboratory (now Lawrence Berkeley National Laboratory) and invented the cyclotron, which won him the Nobel physics prize in 1939. As a result of the discovery, UC Berkeley and Berkeley Lab scientists and researchers, went on to discover 16 chemical elements of the periodic table – more than any other university in the world. In particular the period during World War II and following was a rich time for element discovery at Berkeley. After College of Chemistry and Nobel Laureate Glenn Seaborg and his team (including Darleane Hoffman) discovered Plutonium, Lawrence's Radiation Laboratory began to contract with the U.S. Army to develop the atomic bomb which became know as the Manhattan Project. UC Berkeley physics professor Robert Oppenheimer was named scientific head of the Project in 1942. As part of the project, Seaborg, Albert Ghiorso, and Stanley Thompson went on to discover Curium, Americium, and Berkelium in the 1940s.
In 1950, Seaborg, Thompson and Ghiorso, discovered another radioactive element which was named Californium. This metallic chemical element has been widely used from being a neutron startup source for nuclear reactors, to the treatment of brain and cervical cancers. Scientists at the Berkeley and Los Alamos Labs went on to discover Einsteinium, Fermium, Mendelevium, Lawrencium, Rutherfordium, and Dubnium. In 1974, element 106, Seaborgium (named for Glenn Seaborg), was officially added.
The story of the Periodic Table is far from over. So many glories of the universe have yet to be revealed. Learn more about the history of the Periodic Table here.