Rutherfordium

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 known isotope, 267Rf, has a half-life of approximately 1.3 hours.
Symbol: Rf
Electron configuration: Rn 5f14 6d2 7s2
Discovered: 1964
Atomic number: 104
CAS ID: 53850-36-5
Atomic mass: 261 u