Neptunium Elemental Symbol
Neptunium



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Neptunium Neptunium Nettunio Neptúnio Neptunio Neptunium

Neptunium Bohr ModelNeptunium has the atomic symbol Np, atomic number 93, and atomic weight 237. It is a Block F, Group 3, Period 7 element. The number of electrons in each of Neptunium's shells is 2, 8, 18, 32, 22, 9, 2 and its electron configuration is [Rn] 5f4 6d1 7s2. The neptunium atom has a Van der Waals radius of 221.pm. In its elemental form, CAS 7439-99-8, neptunium has a silvery metallic appearance. The element was discovered by Edwin M. McMillan and P. H. Abelson in 1940. It was the first synthetic transuranium element of the actinide series discovered and was named for the planet Neptune.

Neptunium 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

Neptunium Properties


GENERAL PROPERTIES   PHYSICAL PROPERTIES  
Symbol: Np Melting Point: 644 oC, 1191.2 oF, 917.15 K
Atomic Number: 93 Boiling Point: 644 oC, 1191.2 oF, 917.15 K
Atomic Weight: 237 Density: 20450 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 336 kJ·mol−1
CHEMICAL STRUCTURE Heat of Fusion 3.20 kJ·mol−1
Electrons: 93 Thermal Conductivity: 6.3 W·m−1·K−1
Protons: 93 Thermal Expansion: N/A
Neutrons: 144 Electrical Resistivity: (22 °C) 1.220 µΩ·m
Electron Configuration: [Rn] 5f46d17s2 Electronegativity: 1.36 (Pauling scale)
Atomic Radius: 155 pm Tensile Strength: N/A
Covalent Radius: 190±1 pm Molar Heat Capacity: 29.46 J·mol−1·K−1
Van der Waals radius: 221 pm Young's Modulus: N/A
Oxidation States: 6, 5, 4, 3 Shear Modulus: N/A
Phase: Solid  Bulk Modulus: N/A
Crystal Structure: orthorhombic Poisson Ratio: N/A
Magnetic Ordering: paramagnetic Mohs Hardness: N/A
1st Ionization Energy: 604.5 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
       
IDENTIFIERS   MISCELLANEOUS  
CAS Number: 7439-99-8 Abundance in typical human body, by weight: N/A
ChemSpider ID: 22375 Abundance in typical human body, by atom: N/A
PubChem CID: 23933 Abundance in universe, by weight: N/A
MDL Number: N/A Abundance in universe, by atom: N/A
EC Number: N/A Discovered By: Edwin McMillan and Philip H. Abelson
Beilstein Number: N/A Discovery Date: 1940
SMILES Identifier: [Np]  
InChI Identifier: InChI=1S/Np Other Names: Nettunio
InChI Key: LFNLGNPSGWYGGD-UHFFFAOYSA-N  
       
       
       
       
       


Recent Research & Development for Neptunium

  • Pan Zeng, Yuancheng Teng, Yi Huang, Lang Wu, Xiaohuan Wang, Synthesis, phase structure and microstructure of monazite-type Ce1-xPrxPO4 solid solutions for immobilization of minor actinide neptunium, Journal of Nuclear Materials, Volume 452, Issues 1–3, September 2014
  • Yingjie Zhang, Daniel J. Gregg, Gregory R. Lumpkin, Bruce D. Begg, Miodrag Jovanovic, The incorporation of neptunium and plutonium in thorutite (ThTi2O6), Journal of Alloys and Compounds, Volume 581, 25 December 2013
  • Hirokazu Hayashi, Masahide Takano, Masaki Kurata, Kazuo Minato, Syntheses of neptunium trichloride and measurements of its melting temperature, Journal of Nuclear Materials, Volume 440, Issues 1–3, September 2013
  • A. Filanovich, A. Povzner, The influence of phonon anharmonicity on thermal and elastic properties of neptunium, Journal of Nuclear Materials, Volume 437, Issues 1–3, June 2013
  • Akihiro Uehara, Takayuki Nagai, Toshiyuki Fujii, Osamu Shirai, Hajimu Yamana, Spectrophotometric and electrochemical study of neptunium ions in molten NaCl–CsCl eutectic, Journal of Nuclear Materials, Volume 437, Issues 1–3, June 2013
  • Daniel S. Alessi, Jennifer E.S. Szymanowski, Tori Z. Forbes, Andrew N. Quicksall, Ginger E. Sigmon, Peter C. Burns, Jeremy B. Fein, Mineralogic controls on aqueous neptunium(V) concentrations in silicate systems, Journal of Nuclear Materials, Volume 433, Issues 1–3, February 2013
  • Mathew S. Snow, Pihong Zhao, Zurong Dai, Annie B. Kersting, Mavrik Zavarin, Neptunium(V) sorption to goethite at attomolar to micromolar concentrations, Journal of Colloid and Interface Science, Volume 390, Issue 1, 15 January 2013
  • Florent Lebreton, Damien Prieur, Aurélien Jankowiak, Magaly Tribet, Caroline Leorier, Thibaud Delahaye, Louis Donnet, Philippe Dehaudt, Fabrication and characterization of americium, neptunium and curium bearing MOX fuels obtained by powder metallurgy process, Journal of Nuclear Materials, Volume 420, Issues 1–3, January 2012
  • Geng Bang Jin, Adam D. Raw, S. Skanthakumar, Richard G. Haire, L. Soderholm, James A. Ibers, Single-crystal structures of uranium and neptunium oxychalcogenides AnOQ (An=U, Np; Q=S, Se), Journal of Solid State Chemistry, Volume 183, Issue 3, March 2010
  • Edgar C. Buck, Matt Douglas, Rick S. Wittman, Verifying the presence of low levels of neptunium in a uranium matrix with electron energy-loss spectroscopy, Micron, Volume 41, Issue 1, January 2010

Neptunium Isotopes


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