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The mineralogy of Curium

About Curium
Curium is a radioactive transuranic element that has only been produced in nuclear reactors. It is possible that some curium and other transuranic elements were created in the natural nuclear reactor in Oklo, Gabon.

General Properties
Symbol:	Cm
Atomic Number:	96
Standard atomic weight (A_r):	[247]
Electron configuration:	[Rn] 5f⁷ 6d¹ 7s²

Photos

A piece of curium

Atomic Properties
Electronegativity (Pauling scale):	1.3
Atomic Radius:	174 pm
Ionic Radius:	97 pm (+3)
1st Ionization energy:	581 kJ/mol
Oxidation States:	3,4

Physical Properties
Standard State:	solid
Bonding Type:	metallic
Melting Point:	1618 K
Boiling Point:	3383 K
Density:	13.51 g/cm³
Metal/Non-Metal:	actinoid

Main isotopes of Curium
Isotope	% in Nature	Half Life	Decay type	Decay product
²⁴²Cm	synthetic	160d	Spontaneous fission
²⁴²Cm	synthetic	160d	α	²³⁸Pu
²⁴³Cm	synthetic	29.1y	α	²³⁹Pu
			ε	²⁴³Am
			Spontaneous fission
²⁴⁴Cm	synthetic	18.1y	Spontaneous fission
²⁴⁴Cm	synthetic	18.1y	α	²⁴⁰Pu
²⁴⁵Cm	synthetic	8500y	Spontaneous fission
²⁴⁵Cm	synthetic	8500y	α	²⁴¹Pu
²⁴⁶Cm	synthetic	4730y	α	²⁴²Pu
²⁴⁶Cm	synthetic	4730y	Spontaneous fission
²⁴⁷Cm	synthetic	1.46×10⁷y	α	²³⁴Pu
²⁴⁸Cm	synthetic	3.4×10⁵y	α	²⁴⁴Pu
²⁴⁸Cm	synthetic	3.4×10⁵y	Spontaneous fission
²⁵⁰Cm	synthetic	9000y	Spontaneous fission
			α	²⁴⁶Pu
			β−	²⁵⁰Bk

Main ions of Curium
Name	Ion	Example minerals
curium(II)	Cm²⁺
curium(III)	Cm³⁺
curium(IV)	Cm⁴⁺

Other Information
Year Discovered:	1944
Discovered By:	Glenn T. Seaborg Albert Ghiorso Glenn T. Seaborg, Ralph A. James, Albert Ghiorso
Named For:	Pierre Curie Marie Skłodowska Curie Marie Sklodowska-Curie and Pierre Curie
CPK color coding:	#785CE3
External Links:	Wikipedia WebElements Los Alamos National Laboratory Theodore Gray's PeriodicTable.com

Simple Compounds
Fluorides	curium trifluoride	CmF₃	+3
Fluorides	curium tetrafluoride	CmF₄	+4
Chlorides	curium trichloride	CmCl₃	+3
Iodides	curium triiodide	CmI₃	+3
Oxides	curium oxide	CmO	+2
	curium dioxide	CmO₂	+4
	dicurium trioxide	Cm₂O₃	+3

Periodic Table

2He

3Li

4Be

Show/hide current element

Default Categories CPK Electronegativity Atomic Radius Lowest Oxidation Highest Oxidation Crustal Abundance Goldschmidt Mineral Species

Americium << Curium >> Berkelium

Spotted a mistake/omission? - These pages are a work in progress, so please send all comments/corrections to jolyon@mindat.org. Thank you.

Constants and physical property data from:

Lide, David R. - Ed. (2005) CRC Handbook of Chemistry and Physics - A Ready-Reference Book of Chemical and Physical Data (85th ed.). CRC Press.
National Physical Laboratory (2005) Kaye and Laby Online (discontinued). https://web.archive.org/web/20190506031327/http://www.kayelaby.npl.co.uk/
Kaye, G. W. C.; Laby, T. H. (n.d.) Tables of Physical and Chemical Constants and some Mathematical Functions. Longmans, Green, and Co.
Greenwood, N.N.; Earnshaw, A. (1997) Chemistry of the Elements (2nd ed.). Butterworth–Heinemann.
Ahrens, Thomas J. - Ed. (1995) Global Earth Physics - A Handbook of Physical Constants - AGU Reference Shelf No. 1. American Geophysical Union.
Railsback, L. Bruce (2003) An earth scientist's periodic table of the elements and their ions. Geology, 31 (9) 737 doi:10.1130/g19542.1
Emsley, John (2001) Nature's Building Blocks - An A-Z Guide to the Elements. Oxford University Press, Oxford.

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