This is the only element in the periodic table named after a small Russian town. Dubna sits on the Volga River — a quiet science city where physicists from around the world created the heaviest atoms on Earth. Element 105 was first synthesized here in 1968. Its most stable isotope, Db-268, lives 32 hours — a record among the first superheavy elements. Chemically, dubnium resembles tantalum, its lighter cousin in group 5.
Dubnium is synthesized in accelerators by bombarding americium-243 with neon ions. Its most stable isotope, Db-268, lives about 32 hours — a record for transactinides. This gives scientists a window for chemical experiments.
Dubnium's chemical behavior turned out to be surprising. Theory predicted it would resemble tantalum, but some experiments show deviations — possibly due to relativistic effects. This puzzle remains unsolved.
Dubnium is extremely radioactive. Only a few atoms are synthesized at a time, existing from seconds to hours. It poses no practical health threat — available only in a handful of labs worldwide in microscopic quantities.
Dubna — a town of just 75,000 people — became the only small city to have a chemical element named after it. Physicists from 18 countries work at its nuclear research institute.
Isotope Db-268 lives 32 hours — a record among the first five transactinide elements. That's enough time for a full chemical experiment.
Like rutherfordium, dubnium's name was disputed for decades. Americans called it hahnium (after Otto Hahn), Russians — nielsbohrium. The compromise took 27 years.
Dubna is a city on the Volga River, home to the Joint Institute for Nuclear Research. Scientists from 18 countries work here and have discovered more superheavy elements than anywhere else in the world.
32 hours of half-life is an eternity for superheavy elements. Most of dubnium's neighbors live for seconds or milliseconds. This 'longevity' makes chemical studies possible.
| Isotope | Mass (u) | Abundance | Half-life | Decay |
|---|---|---|---|---|
262Db☢ | 262.114070 | synthetic | 34 seconds | α/SF |
268Db☢ | 268.125670 | synthetic | 32 hours | SF |
Cyclotron bombardment of californium