noun Chemistry, Physics.
any element having an atomic number higher than 103, the last of the actinide series. These superheavy, radioactive elements are extremely short-lived, and can only be created in the laboratory.
Why is a new element named after a suburb of San Francisco?
On Saturday the International Union of Pure and Applied Chemistry proposed the names of two new elements. Currently element number 114 and element number 116 do not have official names in the periodic table of elements. The elements were previously known as ununquadium and ununhexium. Those long, unpronounceable words were the temporarily used systematic element names. The names are generated from their atomic number, but …
Read more in this article about some frequently asked questions and fun facts related to our definitions.
See also transuranic element.
Origin of transactinide element
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019