As of February 2015, there are 26 man-made elements listed on the periodic table. The actinide series includes neptunium, polonium, americium, curium and berkelium. Californium, einsteinium, fermium, mendelevium, nobelium and lawrencium are also found in the actinide series. Elements 104 through 118 are located in period 7 of the periodic table. Man-made elements in period 7 include rutherfordium, ununtrium, flerovium and ununoctium.
Man-made elements are not usually found in nature, but scientists have determined that some of them are produced naturally in very small quantities. All of the man-made elements are radioactive and have the ability to undergo nuclear fission. Scientists use nuclear reactors and particle accelerators to produce these elements.
Many of the man-made elements are named after scientists or historical figures. Curium, first identified in 1944, was named after Marie and Pierre Curie. Rutherfordium was named after Ernest Rutherford, the father of nuclear physics. Researchers identified rutherfordium by bombarding plutonium with neon ions. Einsteinium gets its name from theoretical physicist Albert Einstein. Researchers from Berkeley identified einsteinium in the debris created by a thermonuclear explosion.Learn more about Atoms & Molecules