Curium

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Curium,  96Cm
General properties
Pronunciation/ˈkjʊəriəm/ (KEWR-ee-əm)
Appearancesilvery metallic, glows purple in the dark
Mass number247 (most stable isotope)
Curium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Gd

Cm

(Upn)
americiumcuriumberkelium
Atomic number (Z)96
Groupgroup n/a
Periodperiod 7
Blockf-block
Element category  actinide
Electron configuration[Rn] 5f7 6d1 7s2
Electrons per shell
2, 8, 18, 32, 25, 9, 2
Physical properties
Phase at STPsolid
Melting point1613 K ​(1340 °C, ​2444 °F)
Boiling point3383 K ​(3110 °C, ​5630 °F)
Density (near r.t.)13.51 g/cm3
Heat of fusion13.85 kJ/mol
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1788 1982
Atomic properties
Oxidation states+2, +3, +4, +5,[1] +6,[2] (an amphoteric oxide)
ElectronegativityPauling scale: 1.3
Ionization energies
  • 1st: 581 kJ/mol
Atomic radiusempirical: 174 pm
Covalent radius169±3 pm
Color lines in a spectral range
Spectral lines of curium
Other properties
Natural occurrencesynthetic
Crystal structuredouble hexagonal close-packed (dhcp)
Double hexagonal close packed crystal structure for curium
Electrical resistivity1.25 µΩ·m[3]
Magnetic orderingantiferromagnetic-paramagnetic transition at 52 K[3]
CAS Number7440-51-9
History
Namingnamed after Marie Skłodowska-Curie and Pierre Curie
DiscoveryGlenn T. Seaborg, Ralph A. James, Albert Ghiorso (1944)
Main isotopes of curium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
242Cm syn 160 d SF
α 238Pu
243Cm syn 29.1 y α 239Pu
ε 243Am
SF
244Cm syn 18.1 y SF
α 240Pu
245Cm syn 8500 y SF
α 241Pu
246Cm syn 4730 y α 242Pu
SF
247Cm syn 1.56×107 y α 243Pu
248Cm syn 3.40×105 y α 244Pu
SF
250Cm syn 9000 y SF
α 246Pu
β 250Bk
| references

Curium is a chemical element. It is a radioactive metal. It has the chemical symbol Cm. It has the atomic number 96. 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 to be made. Curium has a silver color. Curium is made by bombarding a plutonium target with alpha particles (helium ions). Curium was named after Marie Curie and her husband Pierre.

References[change | change source]

  1. 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. 
  2. 2.0 2.1 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. 
  3. 3.0 3.1 Schenkel, R. (1977). "The electrical resistivity of 244Cm metal". Solid State Communications 23 (6): 389. doi:10.1016/0038-1098(77)90239-3. 
  4. 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.