Bohrium
Bohrium is named after Niels Bohr, the Danish physicist who developed the quantum model of the atom. It was first produced in 1981 at GSI (Gesellschaft für Schwerionenforschung) in Darmstadt, Germany.
- Atomic Number107107 protons, 107 electrons
- Atomic Mass270.133 uOver 107× heavier than hydrogen
- State at Room TempSolidpredicted solid
- DensityNot measuredPredicted from periodic trends
- Melting / BoilingNot yet measuredDecays in milliseconds to hours
- Discovered1976First produced 1973s
What is Bohrium?
Bh-270 has a half-life of approx. 61 seconds. Only a few atoms have ever been made. It is predicted to be a solid transition metal.
With 107 protons, Bohrium sits in Group 7 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 Bohrium
On Earth
Bohrium 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 Bohrium
Bohrium 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
Bh-270 has a half-life of approx. 61 seconds. Only a few atoms have ever been made. It is predicted to be a solid transition metal.
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 108 protons on the periodic table brings us to the next superheavy element.