Californium (Cf, Z = 98)
98
Cf
251,000 u
Actinide Bloc f Groupe 3 Période 7 Solide (CNTP)
Californium is a radioactive metallic chemical element with symbol Cf and atomic number 98. The element was first made in 1950 at the University of California Radiation Laboratory in Berkeley, by bombarding curium with alpha particles (helium-4 ions). It is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye (after einsteinium).
Découvreur : Lawrence Berkeley National Laboratory
Propriétés physiques
- Masse atomique standard
- 251,0 u
- Densité
- 15,10 g/cm³
- Point de fusion
- 1 173,0 K
- Point d'ébullition
- 1 743,0 K
- Chaleur molaire
- —
- Électronégativité (Pauling)
- 1,300
- Affinité électronique
- -97,31 kJ/mol
- Énergies d'ionisation
- 608 kJ/mol
- Configuration électronique
- [Rn] 5f10 7s2
- Électrons par couche
- K : 2 · L : 8 · M : 18 · N : 32 · O : 28 · P : 8 · Q : 2
- Aspect
- silvery
Isotopes (20)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 237Cf | 237 | 139 | 237,062199 | — | 0.8 s | 5/2 | ⁺ | — |
| 238Cf | 238 | 140 | 238,061490 | — | 21.1 ms | 0 | ⁺ | — |
| 239Cf | 239 | 141 | 239,062482 | — | 28 s | 5/2 | ⁺ | — |
| 240Cf | 240 | 142 | 240,062253 | — | 40.3 s | 0 | ⁺ | — |
| 241Cf | 241 | 143 | 241,063690 | — | 2.35 min | 7/2 | ⁻ | — |
| 242Cf | 242 | 144 | 242,063755 | — | 3.49 min | 0 | ⁺ | — |
| 243Cf | 243 | 145 | 243,065475 | — | 10.8 min | 1/2 | ⁺ | — |
| 244Cf | 244 | 146 | 244,065999 | — | 19.5 min | 0 | ⁺ | — |
| 245Cf | 245 | 147 | 245,068047 | — | 45 min | 1/2 | ⁺ | — |
| 246Cf | 246 | 148 | 246,068804 | — | 35.7 h | 0 | ⁺ | — |
| 247Cf | 247 | 149 | 247,070971 | — | 3.11 h | 7/2 | ⁺ | — |
| 248Cf | 248 | 150 | 248,072183 | — | 333.5 j | 0 | ⁺ | — |
| 249Cf | 249 | 151 | 249,074850 | — | 351 an | 9/2 | ⁻ | — |
| 250Cf | 250 | 152 | 250,076404 | — | 13.08 an | 0 | ⁺ | — |
| 251Cf | 251 | 153 | 251,079587 | — | 898 an | 1/2 | ⁺ | — |
| 252Cf | 252 | 154 | 252,081627 | — | 2.645 an | 0 | ⁺ | — |
| 253Cf | 253 | 155 | 253,085134 | — | 17.81 j | 7/2 | ⁺ | — |
| 254Cf | 254 | 156 | 254,087324 | — | 60.5 j | 0 | ⁺ | — |
| 255Cf | 255 | 157 | 255,091046 | — | 85 min | 7/2 | ⁺ | — |
| 256Cf | 256 | 158 | 256,093442 | — | 12.3 min | 0 | ⁺ | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.