Curium, 00Cm|
| Pronunciation | (KURE-ee-əm) |
|---|
| Appearance | silvery metallic, glows purple in the dark |
|---|
| Mass number | [247] |
|---|
|
|
|
| Group | f-block groups (no number) |
|---|
| Period | period 7 |
|---|
| Block | f-block |
|---|
| Electron configuration | [Rn] 5f7 6d1 7s2 |
|---|
| Electrons per shell | 2, 8, 18, 32, 25, 9, 2 |
|---|
|
| Phase at STP | solid |
|---|
| Melting point | 1613 K (1340 °C, 2444 °F) |
|---|
| Boiling point | 3383 K (3110 °C, 5630 °F) |
|---|
| Density (near r.t.) | 13.51 g/cm3 |
|---|
| Heat of fusion | 13.85 kJ/mol |
|---|
Vapor pressure
| P (Pa)
|
1
|
10
|
100
|
1 k
|
10 k
|
100 k
|
| at T (K)
|
1788
|
1982
|
|
|
|
|
|
|
| Oxidation states | +3, +4, +5,[1] +6[2] (an amphoteric oxide) |
|---|
| Electronegativity | Pauling scale: 1.3 |
|---|
| Ionization energies | |
|---|
| Atomic radius | empirical: 174 pm |
|---|
| Covalent radius | 169±3 pm |
|---|
| Spectral lines of curium |
|
| Natural occurrence | synthetic |
|---|
| Crystal structure | double hexagonal close-packed (dhcp) |
|---|
| Electrical resistivity | 1.25 µΩ⋅m[3] |
|---|
| Magnetic ordering | antiferromagnetic-paramagnetic transition at 52 K[3] |
|---|
| CAS Number | 7440-51-9 |
|---|
|
| Naming | named after Marie Skłodowska-Curie and Pierre Curie |
|---|
| Discovery | Glenn T. Seaborg, Ralph A. James, Albert Ghiorso (1944) |
|---|
|
|
| Main isotopes[4]
|
Decay
|
|
|
abundance
|
half-life (t1/2)
|
mode
|
product
|
| 242Cm
|
synth
|
162.8 d
|
α
|
238Pu
|
| SF
|
–
|
| 34Si
|
...
|
| 243Cm
|
synth
|
29.1 y
|
α
|
239Pu
|
| ε
|
243Am
|
| SF
|
–
|
| 244Cm
|
synth
|
18.11 y
|
α
|
240Pu
|
| SF
|
–
|
| 245Cm
|
synth
|
8250 y
|
α
|
241Pu
|
| SF
|
–
|
| 246Cm
|
synth
|
4060 y
|
α
|
242Pu
|
| SF
|
–
|
| 247Cm
|
synth
|
1.56×107 y
|
α
|
243Pu
|
| 248Cm
|
synth
|
3.480×105 y
|
α
|
244Pu
|
| SF
|
–
|
| 250Cm
|
synth
|
8300 y
|
SF
|
–
|
| α
|
246Pu
|
| β−
|
250Bk
| |
|
|
|
Curium is a synthetic chemical element in the periodic table that has the atomic number 96. It has the chemical symbol Cm and it is a radioactive metal. In chemistry it is placed in a group of metal elements named the actinides. Curium is a transuranic element. It is a radioactive element that does not exist in nature. Curium has a silver color and it is made by bombarding a plutonium target with alpha particles (helium ions). Curium was named after Marie Curie and her husband Pierre.
Uses
Curium is used currently in rovers and space machinery.
References
- ↑ 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.
- ↑ Domanov, V. P.; Lobanov, Yu. V. (October 2011). "Formation of volatile curium(VI) trioxide CmO3". Radiochemistry. 53 (5). SP MAIK Nauka/Interperiodica: 453–6. doi:10.1134/S1066362211050018. S2CID 98052484.
- ↑ 3.0 3.1 Schenkel, R. (1977). "The electrical resistivity of 244Cm metal". Solid State Communications. 23 (6): 389. Bibcode:1977SSCom..23..389S. doi:10.1016/0038-1098(77)90239-3.
- ↑ 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.
- ↑ Domanov, V. P.; Lobanov, Yu. V. (October 2011). "Formation of volatile curium(VI) trioxide CmO3". Radiochemistry. 53 (5). SP MAIK Nauka/Interperiodica: 453–6. doi:10.1134/S1066362211050018.
- ↑ 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.