Americium Elemental Symbol

French German Italian Portuguese Spanish Swedish
Américium Americium Americio Amerício Americio Americium

Americium Bohr ModleAmericium is a Block F, Group 3, Period 7 element. The number of electrons in each of Americium's shells is 2, 8, 18, 32, 25, 8, 2 and its electron configuration is [Rn] 5f7 7s2. The americium atom has a radius of and it's Van der Waals radius is In its elemental form, CAS 7440-35-9, americium has a silvery white appearance. Americium was discovered by Glenn T. Seaborg, Ralph A. James, Stanley G. Thompson and Albert Ghiorso in 1944. It was the fourth synthetic transuranic element to be discovered and was named after the continent of North America.

Americium is artificially produced in small quantities for research purposes. Due to its radioactivity, americium is harmful. Americium information, including technical data, safety data and its high purity properties, research, applications and other useful facts are discussed below. Scientific facts such as the atomic structure, ionization energy, abundance on earth, conductivity and thermal properties are included.

  • Properties
  • Research
  • Isotopes
  • Other Elements

Americium Properties

Symbol: Am Melting Point: 1176 oC, 2148.8 oF, 1449.15 K
Atomic Number: 95 Boiling Point: 2011 oC, 3651.8 oF, 2284.15 K
Atomic Weight: 243 Density: 13670 kg m-3
Element Category: Actinide Liquid Density @ Melting Point: N/A
Group, Period, Block: n/a, 7, f Specific Heat: N/A
    Heat of Vaporization N/A
CHEMICAL STRUCTURE Heat of Fusion 14.39 kJ·mol−1
Electrons: 95 Thermal Conductivity: 10 W·m−1·K−1
Protons: 95 Thermal Expansion: N/A
Neutrons: 148 Electrical Resistivity: 0.69 µΩ·m
Electron Configuration: [Rn] 5f77s2 Electronegativity: 1.3 (Pauling scale)
Atomic Radius: 173 pm Tensile Strength: N/A
Covalent Radius: 180±6 pm Molar Heat Capacity: 62.7 J·mol−1·K−1
Van der Waals radius: 244 pm Young's Modulus: N/A
Oxidation States: 6, 5, 4, 3, 0 Shear Modulus: N/A
Phase: Solid  Bulk Modulus: N/A
Crystal Structure: hexagonal Poisson Ratio: N/A
Magnetic Ordering: paramagnetic Mohs Hardness: N/A
1st Ionization Energy: 578 kJ·mol−1 Vickers Hardness: N/A
2nd Ionization Energy: N/A Brinell Hardness: N/A
3rd Ionization Energy: N/A Speed of Sound: N/A
CAS Number: 7440-35-9 Abundance in typical human body, by weight: N/A
ChemSpider ID: 22405 Abundance in typical human body, by atom: N/A
PubChem CID: 23966 Abundance in universe, by weight: N/A
MDL Number: N/A Abundance in universe, by atom: N/A
EC Number: N/A Discovered By: Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso
Beilstein Number: N/A Discovery Date: 1944
SMILES Identifier: [Am]  
InChI Identifier: InChI=1S/Am Other Names: Americio

Recent Research & Development for Americium

  • Evidence for covalence in a N-donor complex of americium(iii). Adam C, Kaden P, Beele BB, Müllich U, Trumm S, Geist A, Panak PJ, Denecke MA. Dalton Trans. 2013 Jun 10. [Epub ahead of print]
  • Isotopic ratio correlation for the isotopic composition analysis of plutonium in Am-Pu mixed samples having High americium content. Patra S, Agarwal C, Chaudhury S, Newton Nathaniel T, Gathibandhe M, Goswami A. Appl Radiat Isot. 2013 Aug;78:139-44. doi: 10.1016/j.apradiso.2013.04.007. Epub 2013 Apr 17.
  • Role of cation interactions in the reduction process in plutonium-americium mixed oxides. Belin RC, Martin PM, Lechelle J, Reynaud M, Scheinost AC. Inorg Chem. 2013 Mar 18;52(6):2966-72. doi: 10.1021/ic3023776. Epub 2013 Feb 26.
  • Selectivity of bis-triazinyl bipyridine ligands for americium(III) in Am/Eu separation by solvent extraction. Part 1. Quantum mechanical study on the structures of BTBP complexes and on the energy of the separation. Narbutt J, Oziminski WP. Dalton Trans. 2012 Dec 21;41(47):14416-24. doi: 10.1039/c2dt31503c.
  • Charge distribution and local structure of americium-bearing thorium oxide solid solutions. Carvajal-Nunez U, Prieur D, Vitova T, Somers J. Inorg Chem. 2012 Nov 5;51(21):11762-8. doi: 10.1021/ic301709d. Epub 2012 Oct 16.
  • Separation of americium from curium by oxidation and ion exchange. Burns JD, Shehee TC, Clearfield A, Hobbs DT. Anal Chem. 2012 Aug 21;84(16):6930-2. doi: 10.1021/ac3018394. Epub 2012 Jul 31.
  • Syntheses, structures, and spectroscopic properties of plutonium and americium phosphites and the redetermination of the ionic radii of Pu(III) and Am(III). Cross JN, Villa EM, Wang S, Diwu J, Polinski MJ, Albrecht-Schmitt TE. Inorg Chem. 2012 Aug 6;51(15):8419-24. doi: 10.1021/ic300958z. Epub 2012 Jul 17.
  • Effects of americium-241 and humic substances on Photobacterium phosphoreum: bioluminescence and diffuse reflectance FTIR spectroscopic studies. Kamnev AA, Tugarova AV, Selivanova MA, Tarantilis PA, Polissiou MG, Kudryasheva NS. Spectrochim Acta A Mol Biomol Spectrosc. 2013 Jan 1;100:171-5. doi: 10.1016/j.saa.2012.06.003. Epub 2012 Jun 15.
  • Periodic trends in lanthanide and actinide phosphonates: discontinuity between plutonium and americium. Diwu J, Grant DJ, Wang S, Gagliardi L, Albrecht-Schmitt TE. Inorg Chem. 2012 Jun 18;51(12):6906-15. doi: 10.1021/ic300742p. Epub 2012 Jun 5.
  • A highly efficient solvent system containing functionalized diglycolamides and an ionic liquid for americium recovery from radioactive wastes. Sengupta A, Mohapatra PK, Iqbal M, Huskens J, Verboom W. Dalton Trans. 2012 Jun 21;41(23):6970-9. doi: 10.1039/c2dt12364a. Epub 2012 Apr 25.
  • Investigation of factors affecting the quality of americium electroplating. Trdin M, Benedik L, Samardžija Z, Pihlar B. Appl Radiat Isot. 2012 Sep;70(9):2002-5. doi: 10.1016/j.apradiso.2012.02.045. Epub 2012 Mar 4.
  • Calcium and zinc DTPA administration for internal contamination with plutonium-238 and americium-241. Kazzi ZN, Heyl A, Ruprecht J. Curr Pharm Biotechnol. 2012 Aug;13(10):1957-63. Review.
  • Curium(III) borate shows coordination environments of both plutonium(III) and americium(III) borates. Polinski MJ, Wang S, Alekseev EV, Depmeier W, Liu G, Haire RG, Albrecht-Schmitt TE. Angew Chem Int Ed Engl. 2012 Feb 20;51(8):1869-72. doi: 10.1002/anie.201107956. Epub 2012 Jan 13. No abstract available.
  • Local structure and charge distribution in mixed uranium-americium oxides: effects of oxygen potential and Am content. Prieur D, Martin PM, Jankowiak A, Gavilan E, Scheinost AC, Herlet N, Dehaudt P, Blanchart P. Inorg Chem. 2011 Dec 19;50(24):12437-45. doi: 10.1021/ic200910f. Epub 2011 Nov 16.
  • Kinetics of plutonium and americium sorption to natural clay. Lujaniene G, Beneš P, Štamberg K, Šciglo T. J Environ Radioact. 2012 Jun;108:41-9. doi: 10.1016/j.jenvrad.2011.07.012. Epub 2011 Sep 21.
  • Bonding changes in plutonium(III) and americium(III) borates. Polinski MJ, Wang S, Alekseev EV, Depmeier W, Albrecht-Schmitt TE. Angew Chem Int Ed Engl. 2011 Sep 12;50(38):8891-4. doi: 10.1002/anie.201103502. Epub 2011 Aug 18. No abstract available.
  • Selective recognition of americium by peptide-based reagents. Özçubukçu S, Mandal K, Wegner S, Jensen MP, He C. Inorg Chem. 2011 Sep 5;50(17):7937-9. doi: 10.1021/ic201094e. Epub 2011 Aug 5.
  • Higher oxidation states of americium: preparation, characterization and use for separations. Runde WH, Mincher BJ. Chem Rev. 2011 Sep 14;111(9):5723-41. doi: 10.1021/cr100181f. Epub 2011 Jul 5. No abstract available.
  • Complexation of lanthanides(III), americium(III), and uranium(VI) with bitopic N,O ligands: an experimental and theoretical study. Marie C, Miguirditchian M, Guillaumont D, Tosseng A, Berthon C, Guilbaud P, Duvail M, Bisson J, Guillaneux D, Pipelier M, Dubreuil D. Inorg Chem. 2011 Jul 18;50(14):6557-66. doi: 10.1021/ic200271e. Epub 2011 Jun 10.
  • Uncertainty analysis of doses from ingestion of plutonium and americium. Puncher M, Harrison JD. Radiat Prot Dosimetry. 2012 Feb;148(3):284-96. doi: 10.1093/rpd/ncr032. Epub 2011 Apr 14.

Americium Isotopes

Americium is an artificial element. It has no stable isotopes.