This is element
104, symbol Rf
, named after the New-Zealand
-born Ernest Rutherford
. A former rival
name for it was kurchatovium
, after the Soviet physicist Igor Kurchatov
, but rutherfordium is now the official name adopted by IUPAC
Atomic weight: about 264
An artificial element created in 1964 at the the Joint Nuclear Research Institute at Dubna in Russia, and subsequently reported also discovered at Berkeley in the USA in 1969: whence the rival names. Until the IUPAC decided to accept the name rutherfordium, it could also be provisionally called unnilquadium, symbol Unq.
It hasn't been created in macroscopic quantities, but would probably be a silvery metal chemically similar to hafnium.