104
Rf
Rutherfordium
267
Rutherfordium (Rf)
Transition MetalGroup 4Period 7d-block-blockRadioactive
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. In the periodic table of the elements, it is a d - block element and the second of the fourth - row transition elements.
Latin name: Rutherfordium
Atomic Number
104
Atomic Mass
267 g/mol
Phase (STP)
Solid (predicted)
Electron Config.
[Rn] 5f¹⁴ 6d² 7s²
General
SymbolRf
Atomic Number104
Atomic Mass267 g/mol
CategoryTransition Metal
Group4
Period7
Blockd-block
Electron Configuration[Rn] 5f¹⁴ 6d² 7s²
Valence Electrons4
Colourmetallic (predicted)
Physical Properties
Phase (STP)Solid (predicted)
Density23 (predicted)
Melting Point2400 (predicted)
Boiling Point5800 (predicted)
Atomic Properties
Atomic Radius257 pm
Electronegativity1.3 Pauling
Oxidation States+4
Ion ChargeRf4+
Nuclear & Hazards
RadioactiveYes
Half-life1.3 hours (Rf-267)
Abundance
In Earth's Crust0%
Discovery & History
Discovery Year1969
Discovered ByJoint Institute for Nuclear Research and Lawrence Berkeley National Laboratory
Country of DiscoveryUSSR/USA
Isotopes of Rutherfordium
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Rf-261 | — | 68 seconds | α, SF |
| Rf-265 | — | ~1.1 minutes | SF |
| Rf-267 | — | ~1.3 hours | SF |