Donate now to keep alive!Help|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on Mindat
What is a mineral?The most common minerals on earthMineral PhotographyThe Elements and their MineralsGeological TimeMineral Evolution
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

The Mineralogy of Americium

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

General Properties
Atomic Number:95
Standard atomic weight (Ar):[243]
Electron configuration:[Rn] 5f7 7s2
The first sample of americium
Atomic Properties
Electronegativity (Pauling scale):1.3
Atomic Radius:173 pm
Ionic Radius:126 pm (+2)
1st Ionization energy:578 kJ/mol
Oxidation States:2,3,4,5,6
Physical Properties
Standard State:solid
Bonding Type:metallic
Melting Point:1449 K
Boiling Point:2284 K
Density:13.67 g/cm3
Main isotopes of Americium
Isotope% in NatureHalf LifeDecay typeDecay product
241Amsynthetic432.2ySpontaneous fission
Electron capture242Pu
242mAmsynthetic141yIsomeric transition242Am
Spontaneous fission
243Amsynthetic7370ySpontaneous fission
Other Information
Year Discovered:1944
Discovered By:
Glenn T. Seaborg
Albert Ghiorso

Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso
Named For:Americas, because it was discovered in the United States
CPK color coding:#545CF2
External Links:WikipediaWebElementsLos Alamos National LaboratoryTheodore Gray's
Simple Compounds
Fluoridesamericium trifluorideAmF3+3
americium tetrafluorideAmF4+4
Chloridesamericium dichlorideAmCl2+2
americium trichlorideAmCl3+3
Bromidesamericium tribromideAmBr3+3
Iodidesamericium diiodideAmI2+2
americium triiodideAmI3+3
Oxidesamericium oxideAmO+2
americium dioxideAmO2+4
diamericium trioxideAm2O3+3
Periodic Table
1H 2He
3Li 4Be 5B 6C 7N 8O 9F 10Ne
11Na 12Mg 13Al 14Si 15P 16S 17Cl 18Ar
19K 20Ca 21Sc 22Ti 23V 24Cr 25Mn 26Fe 27Co 28Ni 29Cu 30Zn 31Ga 32Ge 33As 34Se 35Br 36Kr
37Rb 38Sr 39Y 40Zr 41Nb 42Mo 43Tc 44Ru 45Rh 46Pd 47Ag 48Cd 49In 50Sn 51Sb 52Te 53I 54Xe
55Cs 56Ba 57La 72Hf 73Ta 74W 75Re 76Os 77Ir 78Pt 79Au 80Hg 81Tl 82Pb 83Bi 84Po 85At 86Rn
87Fr 88Ra 89Ac 104Rd 105Db 106Sg 107Bh 108Hs 109Mt 110Ds 111Rg 112Cn 113Nh 114Fl 115Mc 116Lv 117Ts 118Og
58Ce 59Pr 60Nd 61Pm 62Sm 63Eu 64Gd 65Tb 66Dy 67Ho 68Er 69Tm 70Yb 71Lu
90Th 91Pa 92U 93Np 94Pu 95Am 96Cm 97Bk 98Cf 99Es 100Fm 101Md 102No 103Lr
Default Categories CPK Electronegativity Atomic Radius Lowest Oxidation Highest Oxidation Crustal Abundance Goldschmidt Mineral Species
Plutonium << Americium >> Curium

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

Constants and physical property data from:

David R. Lide (ed.), CRC Handbook of Chemistry and Physics, 85th Edition. CRC Press. Boca Raton, Florida (2005).
Kaye and Laby Tables of Physical & Chemical Constants (2005). Section 3.1.3, Abundances of the elements
A. Earnshaw, N. Greenwood, Chemistry of the Elements, 2nd edition, Butterworth-Heinemann, (1997)
Thomas J. Ahrens (ed.), Global Earth Physics : A Handbook of Physical Constants, American Geophysical Union (1995)
L.B. Railsback, An Earth Scientist's Periodic Table of the Elements and Their Ions : Geology 31:9 p737-740 (2003)
Emsley, J. Nature's Building Blocks: An A-Z Guide to the Elements. New York: Oxford University Press (2001)
Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © and the Hudson Institute of Mineralogy 1993-2018, except where stated. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: January 16, 2018 13:49:11
Go to top of page