Unstable element

• A radioactive transuranic element which has been synthesized

Wiktionary Word definitions in Wiktionary
n. 1 A transuranic chemical element (''symbol'' Rf) with an atomic number of 104 2 (context obsolete English) (non-gloss definition: A rejected name for seaborgium)

Wikipedia Word definitions in Wikipedia
Rutherfordium is a chemical element with symbol Rf and atomic number 104, named in honor of physicist Ernest Rutherford . It is a synthetic element (an element that can be created in a laboratory but is not found in nature) and radioactive ; the most stable ...

WordNet Word definitions in WordNet
n. a radioactive transuranic element which has been synthesized [syn: Rf , kurchatovium , Ku , unnilquadium , Unq , element 104 , atomic number 104 ]

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
kurchatovium \kurchatovium\ n. [From Igor Kurchatov, a Russian scientist who worked on the atomic bomb.] A transuranic element of atomic number 104, symbol Ku; also called rutherfordium , symbol Rf. It is produced in very small quantities by nuclear reactions. ...