Promethium, one of the rarest and most mysterious elements in the periodic table, has finally given up some crucial chemical secrets
One of the rarest and most mysterious elements in the periodic table has finally given up some crucial chemical secrets, eight decades after its discovery. Researchers at Oak Ridge National Laboratory in Tennessee have become the first to use radioactive promethium to make a chemical 'complex' — a compound in which it is bound to a few surrounding molecules. This feat of synthesis enabled the team to study how the element bonds with other atoms in a solution with water. Published May 22 in Nature the findings fill a long-standing gap in chemistry textbooks, and could eventually lead to better methods for separating promethium from similar elements in nuclear waste, for example. "It's a tour de force," says Polly Arnold, a chemist at Lawrence Berkeley National Laboratory in Berkeley, California, who was not involved in the research. Promethium is the most elusive member of the lanthanide family, a row of 15 metals marooned in the periodic table's southern territories. Discovered in 1945, the element was named after the Titan who stole fire from the gods in Greek mythology. Researchers estimate that less than 1 kilogram of it currently exists naturally in the Earth's crust, and its radiation has previously been harnessed to power pacemakers and spacecraft. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Together with a couple of other metals, the lanthanides are collectively known as rare-earth elements, and many are prized for their uses in technology, including lasers and powerful magnets. Although many rare-earth elements are — counter-intuitively — abundant in Earth's crust, they are thinly spread and can be difficult…