Rutherfordium
Rutherfordium is the first transactinide element: the first beyond the actinide series. Named after Ernest Rutherford, who discovered the atomic nucleus. Only a few atoms are made at a time and they decay within seconds to minutes.
- Atomic Number104104 protons, 104 electrons
- Atomic Mass267.122 uOver 104× heavier than hydrogen
- State at Room TempSolidpredicted solid
- DensityNot measuredPredicted from periodic trends
- Melting / BoilingNot yet measuredDecays in milliseconds to hours
- Discovered1964First produced 1964s
What is Rutherfordium?
Rf-267 has a half-life of approx. 1.3 hours. First produced in the 1960s at Dubna (USSR) and Berkeley. Chemistry studies have been done one atom at a time.
With 104 protons, Rutherfordium sits in Group 4 of the periodic table, Period 7, in the superheavy transactinide region. Its properties are predicted largely from theory and from single-atom chemistry experiments, not from bulk measurements.
Where you find Rutherfordium
On Earth
Rutherfordium does not exist naturally. It is made only artificially in nuclear physics laboratories by firing beams of one heavy nucleus at another and watching for the rare collisions that fuse them together. The main laboratories capable of producing superheavy elements are JINR in Dubna (Russia), GSI in Darmstadt (Germany), RIKEN in Japan and Lawrence Livermore National Laboratory in California.
How we use Rutherfordium
Rutherfordium has no practical uses. Only a handful of atoms have ever been produced, each existing for a fraction of a second to a few minutes. Research focuses on understanding nuclear structure, testing theoretical models of the atom, and searching for the predicted "island of stability", a region of superheavy nuclei that may be significantly longer-lived than those currently known.
How it was discovered
Rf-267 has a half-life of approx. 1.3 hours. First produced in the 1960s at Dubna (USSR) and Berkeley. Chemistry studies have been done one atom at a time.
Deeper dive: superheavy elements and the island of stability
Nuclear physicists predict that certain combinations of protons and neutrons, "magic numbers", create particularly stable nuclei. For superheavy elements, a theoretical "island of stability" is predicted around element 114 (flerovium) or beyond, where nuclei with the right magic number of neutrons might have half-lives of years or even longer rather than milliseconds. So far, the search continues. Elements 113-118 were all officially confirmed and named in 2016, completing Period 7 of the periodic table. Whether an eighth period of elements beyond oganesson (118) can ever be made and studied remains one of the great open questions in chemistry and nuclear physics.
Superheavy elements are made by accelerating beams of lighter nuclei (often calcium-48, because of its convenient doubly-magic structure) to high energies and firing them at heavy targets (lead, bismuth, uranium, curium, californium). Very rarely, two nuclei fuse instead of bouncing apart. The fusion product is detected by its characteristic radioactive decay chain, a signature sequence of alpha decays each producing a known element, counted backwards to identify the original product.
Moving to 105 protons on the periodic table brings us to the next superheavy element.