Dubnium is a chemical element with the symbol Db and atomic number 105, named after the town of Dubna in Russia, where it was first produced. 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, dubnium-268, has a half-life of approximately 28 hours.Symbol: Db
Electron configuration: Rn 5f14 6d3 7s2
Atomic number: 105
Discovered: 1967
CAS ID: 53850-35-4
Atomic mass: 262 u