Curium
chemical element with the atomic number of 96
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.
| Curium | ||||||
|---|---|---|---|---|---|---|
| Pronunciation | /ˈkjʊəriəm/ | |||||
| Appearance | silvery metallic, glows purple in the dark | |||||
| Mass number | [247] | |||||
| Curium in the periodic table | ||||||
| ||||||
| 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 | |||||
| Physical properties | ||||||
| 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 pressureTemplate:Center block | ||||||
| Atomic properties | ||||||
| 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 | |||||
 | ||||||
| Other properties | ||||||
| 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 | |||||
| History | ||||||
| Naming | named after Marie Skłodowska-Curie and Pierre Curie | |||||
| Discovery | Glenn T. Seaborg, Ralph A. James, Albert Ghiorso (1944) | |||||
| Isotopes of curium | ||||||
Uses change
Curium is used currently in rovers and space machinery.
References change
- ↑ 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. American Chemical Society. 57 (15): 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. SP MAIK Nauka/Interperiodica. 53 (5): 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.
- ↑ Domanov, V. P.; Lobanov, Yu. V. (October 2011). "Formation of volatile curium(VI) trioxide CmO3". Radiochemistry. SP MAIK Nauka/Interperiodica. 53 (5): 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. American Chemical Society. 57 (15): 9453–9467. doi:10.1021/acs.inorgchem.8b01450.
