A team of scientists working at Lawrence Berkeley National Laboratory (Berkeley Lab) has discovered a new form of the human-made element mendelevium. The newly created isotope, mendelevium-244, is the 17th and lightest form of mendelevium, which is element 101 on the periodic table.
Mendelevium was first created by Berkeley Lab scientists in 1955 (see a related video), and is among a list of 16 other elements that Berkeley Lab scientists discovered or helped to discover. An isotope is a form of an element with more or fewer neutrons (uncharged particles) in its atomic nucleus than other forms of an element.
In the latest discovery, the team used Berkeley Lab's 88-Inch Cyclotron, which accelerates powerful beams of charged particles at targets to create atoms of heavier elements, to make mendelevium-244. A cyclotron is a type of particle accelerator that was invented by the Lab's namesake, Ernest O. Lawrence, in 1930.
Berkeley Lab-led teams have now discovered 12 of the 17 mendelevium
isotopes, and have discovered a total of 640 isotopes—about one-fifth of all known isotopes and by far the highest count for a single institution. At the close of 2019 there were 3,308 known isotopes. The new isotope discovery is the first by a Berkeley Lab-led team since 2010.
