Californium, 98Cf| A very small disc of silvery metal, magnified to show its metallic texture |
|
| Pronunciation | (KAL-ə-FOR-nee-əm) |
|---|
| Appearance | silvery |
|---|
| Mass number | [251] |
|---|
|
|
| Atomic number (Z) | 98 |
|---|
| Group | f-block groups (no number) |
|---|
| Period | period 7 |
|---|
| Block | f-block |
|---|
| Electron configuration | [Rn] 5f10 7s2 |
|---|
| Electrons per shell | 2, 8, 18, 32, 28, 8, 2 |
|---|
|
| Phase at STP | solid |
|---|
| Melting point | 1173 K (900 °C, 1652 °F) |
|---|
| Boiling point | 1743 K (1470 °C, 2678 °F) (estimation)[3] |
|---|
| Density (near r.t.) | 15.1 g/cm3 |
|---|
|
| Oxidation states | common: +3
+2,[4] +4,[4] +5[5][6] |
|---|
| Electronegativity | Pauling scale: 1.3 |
|---|
| Ionization energies | |
|---|
| Color lines in a spectral rangeSpectral lines of californium |
|
| Natural occurrence | synthetic |
|---|
| Crystal structure | double hexagonal close-packed (dhcp) |
|---|
| Mohs hardness | 3–4 |
|---|
| CAS Number | 7440-71-3 |
|---|
|
| Naming | after California, where it was discovered |
|---|
| Discovery | S. G. Thompson, K. Street, Jr., A. Ghiorso and G. T. Seaborg (Lawrence Berkeley National Laboratory) (1950) |
|---|
| First isolation | R. G. Haire and R. D. Baybarz (1974) |
|---|
|
|
| Main isotopes[10]
|
Decay
|
| 248Cf
|
synth
|
333.5 d
|
α100%
|
244Cm
|
| SF<0.01%
|
–
|
| 249Cf
|
synth
|
351 y
|
α100%
|
245Cm
|
| SF≪0.01%
|
–
|
| 250Cf
|
synth
|
13.08 y
|
α99.9%
|
246Cm
|
| SF0.08%
|
–
|
| 251Cf
|
synth
|
898 y
|
α
|
247Cm
|
| 252Cf
|
synth
|
2.645 y
|
α96.9%
|
248Cm
|
| SF3.1%
|
–
|
| 253Cf
|
synth
|
17.81 d
|
β−99.7%
|
253Es
|
| α0.31%
|
249Cm
|
| 254Cf
|
synth
|
60.5 d
|
SF99.7%
|
–
|
| α0.31%
|
250Cm
| |
|
|
File:Symbol category class.svg Category: Californium | references |
| child table, as reused in {IB-Cf} |
|
|
| Main isotopes[10]
|
Decay
|
| 248Cf
|
synth
|
333.5 d
|
α100%
|
244Cm
|
| SF<0.01%
|
–
|
| 249Cf
|
synth
|
351 y
|
α100%
|
245Cm
|
| SF≪0.01%
|
–
|
| 250Cf
|
synth
|
13.08 y
|
α99.9%
|
246Cm
|
| SF0.08%
|
–
|
| 251Cf
|
synth
|
898 y
|
α
|
247Cm
|
| 252Cf
|
synth
|
2.645 y
|
α96.9%
|
248Cm
|
| SF3.1%
|
–
|
| 253Cf
|
synth
|
17.81 d
|
β−99.7%
|
253Es
|
| α0.31%
|
249Cm
|
| 254Cf
|
synth
|
60.5 d
|
SF99.7%
|
–
|
| α0.31%
|
250Cm
| |
|
|
References
These references will appear in the article, but this list appears only on this page.
- ↑
- ↑ 4.0 4.1 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
- ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1265. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
- ↑ Kovács, Attila; Dau, Phuong D.; Marçalo, Joaquim; Gibson, John K. (2018). "Pentavalent Curium, Berkelium, and Californium in Nitrate Complexes: Extending Actinide Chemistry and Oxidation States". Inorg. Chem. 57 (15). American Chemical Society: 9453–9467. doi:10.1021/acs.inorgchem.8b01450. OSTI 1631597. PMID 30040397. S2CID 51717837.
- ↑ 10.0 10.1 Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3) 030001. doi:10.1088/1674-1137/abddae.
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