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.
Quick Facts Pronunciation, Appearance ...
Curium, 00Cm|
Pronunciation | (KURE-ee-əm) |
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Appearance | silvery metallic, glows purple in the dark |
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Mass number | [247] |
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Group | f-block groups (no number) |
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Period | period 7 |
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Block | f-block |
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Electron configuration | [Rn] 5f7 6d1 7s2 |
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Electrons per shell | 2, 8, 18, 32, 25, 9, 2 |
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Phase at STP | solid |
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Melting point | 1613 K (1340 °C, 2444 °F) |
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Boiling point | 3383 K (3110 °C, 5630 °F) |
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Density (near r.t.) | 13.51 g/cm3 |
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Heat of fusion | 13.85 kJ/mol |
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Vapor pressure
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
1788 |
1982 |
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Oxidation states | +3, +4, +5,[1] +6[2] (an amphoteric oxide) |
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Electronegativity | Pauling scale: 1.3 |
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Ionization energies | |
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Atomic radius | empirical: 174 pm |
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Covalent radius | 169±3 pm |
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Spectral lines of curium |
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Natural occurrence | synthetic |
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Crystal structure | double hexagonal close-packed (dhcp) |
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Electrical resistivity | 1.25 µΩ⋅m[3] |
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Magnetic ordering | antiferromagnetic-paramagnetic transition at 52 K[3] |
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CAS Number | 7440-51-9 |
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Naming | named after Marie Skłodowska-Curie and Pierre Curie |
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Discovery | Glenn T. Seaborg, Ralph A. James, Albert Ghiorso (1944) |
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Main isotopes[4] |
Decay |
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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 |
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Category: Curium | references |
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