Dubnium (Db, Z = 105)
105
Db
268,000 u
Métal de transition Bloc d Groupe 5 Période 7 Solide (CNTP)
Dubnium is a chemical element with symbol Db and atomic number 105. It is named after the town of Dubna in Russia (north of Moscow), 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.
Découvreur : Joint Institute for Nuclear Research
Propriétés physiques
- Masse atomique standard
- 268,0 u
- Densité
- 29,30 g/cm³
- Point de fusion
- —
- Point d'ébullition
- —
- Chaleur molaire
- —
- Électronégativité (Pauling)
- —
- Affinité électronique
- —
- Énergies d'ionisation
- —
- Configuration électronique
- *[Rn] 5f14 6d3 7s2
- Électrons par couche
- K : 2 · L : 8 · M : 18 · N : 32 · O : 32 · P : 11 · Q : 2
Isotopes (16)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 255Db | 255 | 150 | 255,106919 | — | 54 ms | 9/2 | ⁺ | — |
| 256Db | 256 | 151 | 256,107674 | — | 1.7 s | 9 | ⁻ | — |
| 257Db | 257 | 152 | 257,107520 | — | 2.3 s | 9/2 | ⁺ | — |
| 258Db | 258 | 153 | 258,108973 | — | 2.17 s | 0 | ⁻ | — |
| 259Db | 259 | 154 | 259,109492 | — | 510 ms | 9/2 | ⁺ | — |
| 260Db | 260 | 155 | 260,111297 | — | 1.52 s | — | — | |
| 261Db | 261 | 156 | 261,111979 | — | 4.7 s | 9/2 | ⁺ | — |
| 262Db | 262 | 157 | 262,114067 | — | 34 s | — | — | |
| 263Db | 263 | 158 | 263,114987 | — | 29 s | 9/2 | ⁺ | — |
| 264Db | 264 | 159 | 264,117297 | — | — | — | — | |
| 265Db | 265 | 160 | 265,118500 | — | — | 9/2 | ⁺ | — |
| 266Db | 266 | 161 | 266,121032 | — | 80 min | — | — | |
| 267Db | 267 | 162 | 267,122399 | — | 2 h | 9/2 | ⁺ | — |
| 268Db | 268 | 163 | 268,125669 | — | 29 h | — | — | |
| 269Db | 269 | 164 | 269,127911 | — | — | 9/2 | ⁺ | — |
| 270Db | 270 | 165 | 270,131399 | — | 1.7 h | — | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.