Protactinium Elemental Symbol

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Protactinium Protactinium Protoattinio Protacnídio Protactinio Protaktinium

Protactinium Bohr ModelProtactinium is a radioactive actinide group metal with the atomic symbol Pa, atomic number 91, and atomic weight 231. It decays by alpha-emission. It is a Block F, Group 3, Period 7 element. The number of electrons in each of Protactinium's shells is 2, 8, 18, 32, 20, 9, 2 and its electron configuration is [Rn] 5f2 6d1 7s2. It has an atomic radius of and a Van der Waals radius is In its elemental form protactinium's CAS number is 7440-13-3. It is found in the form of two isotopes: protactinium-231 and protactinium-234. Protactinium was first predicted by Dmitri Mendeleev in 1869 and first isolated by William Crookes in 1900. It was named by Otto Hahn and Lise Meitner  in 1917. The name Protactinium originates from the Greek word 'Porots' which means first.

Protactinium is both toxic and radioactive. Protactinium 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

Protactinium Properties

Symbol: Pa Melting Point: 1572 oC, 2861.6 oF, 1845.15 K
Atomic Number: 91 Boiling Point: Unknown
Atomic Weight: 231 Density: 15370  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 481 kJ·mol−1
CHEMICAL STRUCTURE Heat of Fusion 12.34 kJ·mol−1
Electrons: 91 Thermal Conductivity: 47 W·m−1·K−1
Protons: 91 Thermal Expansion: N/A
Neutrons: 122 Electrical Resistivity: (0 °C) 177 nΩ·m
Electron Configuration: [Rn] 5f26d17s2 Electronegativity: 1.5 (Pauling scale)
Atomic Radius: 163 Tensile Strength: N/A
Covalent Radius: 200 Molar Heat Capacity: N/A
Van der Waals radius: 243 pm Young's Modulus: N/A
Oxidation States: 5, 4, 3, 2, 0 Shear Modulus: N/A
Phase: Solid  Bulk Modulus: N/A
Crystal Structure: tetragonal Poisson Ratio: N/A
Magnetic Ordering: paramagnetic Mohs Hardness: N/A
1st Ionization Energy: 568 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: 7440-13-3 Abundance in typical human body, by weight: N/A
ChemSpider ID: 22387 Abundance in typical human body, by atom: N/A
PubChem CID: 23945 Abundance in universe, by weight: N/A
MDL Number: N/A Abundance in universe, by atom: N/A
EC Number: N/A Discovered By: William Crookes
Beilstein Number: N/A Discovery Date: 1900
SMILES Identifier: [Pa]  
InChI Identifier: InChI=1S/Pa Other Names: Protoattinio, Protaktinium

Recent Research & Development for Protactinium

  • Thermodynamic Study of the Complexation of Protactinium(V) with Diethylenetriaminepentaacetic Acid. Mendes M, Leguay S, Le Naour C, Hamadi S, Roques J, Moisy P, Guillaumont D, Topin S, Aupiais J, Den Auwer C, Hennig C. Inorg Chem. 2013 Jun 17. [Epub ahead of print]
  • First principles LDA + U and GGA + U study of Protactinium and Protactinium oxides: dependence on the effective U parameter. Obodo KO, Chetty N. J Phys Condens Matter. 2013 Apr 10;25(14):145603. doi: 10.1088/0953-8984/25/14/145603. Epub 2013 Mar 11.
  • Peculiar Protactinium. Wilson R. Nat Chem. 2012 Jun 21;4(7):586. doi: 10.1038/nchem.1389. No abstract available.
  • Thermodynamical and structural study of Protactinium(V) oxalate complexes in solution. Mendes M, Hamadi S, Le Naour C, Roques J, Jeanson A, Den Auwer C, Moisy P, Topin S, Aupiais J, Hennig C, Di Giandomenico MV. Inorg Chem. 2010 Nov 1;49(21):9962-71. doi: 10.1021/ic101189w.
  • Theoretical study on molecular property of Protactinium(V) and uranium(VI) oxocations: why does Protactinium(V) form monooxo cations in aqueous solution? Toraishi T, Tsuneda T, Tanaka S. J Phys Chem A. 2006 Dec 14;110(49):13303-9.
  • Oxidation of gas-phase Protactinium ions, Pa+ and Pa2+: formation and properties of PaO2(2+)(g), protactinyl. Santos M, de Matos AP, Marçalo J, Gibson JK, Haire RG, Tyagi R, Pitzer RM. J Phys Chem A. 2006 May 4;110(17):5751-9.
  • First structural characterization of a Protactinium(V) single oxo bond in aqueous media. Le Naour C, Trubert D, Di Giandomenico MV, Fillaux C, Den Auwer C, Moisy P, Hennig C. Inorg Chem. 2005 Dec 12;44(25):9542-6.
  • Measurement of femtogram quantities of Protactinium in silicate rock samples by multicollector inductively coupled plasma mass spectrometry. Regelous M, Turner SP, Elliott TR, Rostami K, Hawkesworth CJ. Anal Chem. 2004 Jul 1;76(13):3584-9. Erratum in: Anal Chem. 2008 Jan 1;80(1):344.
  • Radioactive waste forms stabilized by ChemChar gasification: characterization and leaching behavior of cerium, thorium, Protactinium, uranium, and neptunium. Marrero TW, Morris JS, Manahan SE. Chemosphere. 2004 Feb;54(7):873-85.
  • Gas-phase chemistry of bare and oxo-ligated Protactinium ions: a contribution to a systematic understanding of actinide chemistry. Gibson JK, Haire RG. Inorg Chem. 2002 Nov 4;41(22):5897-906.
  • Melting of the Earth's lithospheric mantle inferred from Protactinium-thorium-uranium isotopic data Asmerom Y, Cheng H, Thomas R, Hirschmann M, Edwards RL. Nature. 2000 Jul 20;406(6793):293-6.
  • Protactinium-231 and thorium-230 abundances and high scavenging rates in the western arctic ocean Edmonds HN, Moran SB, Hoff JA, Smith JN, Edwards RL. Science. 1998 Apr 17;280(5362):405-7.
  • Protactinium-231 Dating of Carbonates by Thermal Ionization Mass Spectrometry: Implications for Quaternary Climate Change Edwards RL, Cheng H, Murrell MT, Goldstein SJ. Science. 1997 May 2;276(5313):782-6.
  • Calculated optical properties of thorium, Protactinium, and uranium metals. Gasche T, Brooks MS, Johansson B. Phys Rev B Condens Matter. 1996 Jul 15;54(4):2446-2452. No abstract available.
  • Biochemical binding and distribution of Protactinium-233 in the rat. Schuppler U, Planas-Bohne F, Taylor DM. Int J Radiat Biol Relat Stud Phys Chem Med. 1988 Mar;53(3):457-66.
  • Identification of transferrin as the main binding site for Protactinium in rat blood serum. Taylor DM, Farrow LC. Int J Rad Appl Instrum B. 1987;14(1):27-31.
  • Absorption of thorium and Protactinium from the gastrointestinal tract in adult mice and rats and neonatal rats. Sullivan MF, Miller BM, Ryan JL. Health Phys. 1983 Apr;44(4):425-8. No abstract available.
  • The gastrointestinal absorption of Protactinium, uranium, and neptunium in the hamster. Harrison JD, Stather JW. Radiat Res. 1981 Oct;88(1):47-55. No abstract available.
  • Superconducting properties of Protactinium. Smith JL, Spirlet JC, Müller W. Science. 1979 Jul 13;205(4402):188-90.
  • Radiochemical determination of Protactinium-231 in environmental and biological materials. Sill CW. Anal Chem. 1978 Sep;50(11):1559-71. No abstract available.

Protactinium Isotopes

Protactinium has three naturally occurring isotopes, none of them are stable.