Element Dubnium
The Soviet Joint Institute for Nuclear Research (JINR) claimed the first discovery of the element in 1968, followed by the American Lawrence Berkeley Laboratory in 1970
Dubnium is a synthetic chemical element with the symbol Db and atomic number 105
Dubnium is highly radioactive: the most stable known isotope, dubnium-268, has a half-life of about 28 hours. This greatly limits the extent of research on dubnium.
A limited investigation of dubnium chemistry has confirmed this. Solution chemistry experiments have revealed that dubnium often behaves more like niobium rather than tantalum, breaking periodic trends.
Names and Identifiers
| Chemical Formula: | Db |
| CAS: | 53850-35-4 |
| Molecular Weight: | 268.126 g/mol |
| EC Number : | n/a |
| MDL Number: | n/a |
| Color: | unknown (presumably metallic/ silvery white/ gray) |
| Other Names: | Dubnio |
| PubChem CID: | 56951718 |
| IUPAC Name: | Dubnium |
| Inchl: | InChI=1S/Db |
| InChI Key: | PUKKTGLVJQVIOF-UHFFFAOYSA-N |
| Canonical SMILES: | [Db] |
| ICSC Number: | n/a |
Physical & Chemical Properties
| Phase: | Solid |
| Density: | 29.3g/cm³ |
| Boiling Point: | n/a |
| Melting Point: | n/a |
| Molecular Formula: | Db |
| Flash Point: | n/a |
| Exact Mass: | 268 |
Dubnium, having an atomic number of 105, is a superheavy element; like all elements with such high atomic numbers, it is very unstable. The longest-lasting known isotope of dubnium, 268Db, has a half-life of around a day.
Radiosotope data
| Isotope | Mass/Da | Half-life | Mode of decay | Nuclear spin | Nuclear magnetic moment |
|---|---|---|---|---|---|
| 255Db | 255.1074 | 1.6 s | α to 251Lr; SF | ||
| 256Db | 256.1081 | 2.6 s | α to 252Lr; SF; EC to 256Rf | ||
| 257Db | 257.1079 | 1.5 s | α to 253Lr; SF; EC to 257Rf | ||
| 258Db | 258.1093 | 4.2 s | α to 254Lr; SF; EC to 258Rf | ||
| 259Db | 259.1097 | 1.2 s | α to 255Lr | ||
| 260Db | 260.1114 | 1.5 s | α to 256Lr; SF; EC to 260Rf | ||
| 261Db | 261.1121 | 1.8 s | α to 257Lr; SF | ||
| 262Db | 262.11376 (16) | 34 s | α to 258Lr; SF; EC to 262Rf | ||
| 263Db | 263.1153 | 30 s | α to 259Lr; SF |