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 |