Helium Elemental Symbol
Helium



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Héliu Helium Elio Hélio Helio Helium

Helium Bohr ModelHelium is a Block S, Group 18, Period 1 element. The number of electrons in each of Helium's shells is 2 and its electronic configuration is 1s2. In its elemental form helium's CAS number is 7440-59-7. The helium atom has a covalent radius of 28.pm and it's Van der Waals radius is 140.pm. Commercial helium is extracted from natural gas. Helium was discovered by Pierre Janssen and Norman Lockyer in 1868. It was first isolated by William Ramsay, Per Teodor Cleve and Abraham Langlet in 1895.

Helium is not toxic. Helium information, including technical data, safety data and its high purity properties, research, applications and other useful facts are specified below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity and thermal properties are included.


  • Properties
  • Safety Data
  • Research
  • Isotopes
  • Other Elements

Helium Properties


GENERAL PROPERTIES   PHYSICAL PROPERTIES  
Symbol: He Melting Point: -272.2 oC, -457.96 oF, 0.950 K
Atomic Number: 2 Boiling Point: -268.93 oC, -452.074 oF, 4.220 K
Atomic Weight: 4.003 Density: 120 (4.22 K) kg m-3
Element Category: noble gases Liquid Density @ Melting Point: 0.145 g·cm−3
Group, Period, Block: 18, 1, s Specific Heat: N/A
    Heat of Vaporization 0.0829 kJ·mol−1
CHEMICAL STRUCTURE Heat of Fusion 0.0138 kJ·mol−1
Electrons: 2 Thermal Conductivity: 0.1513 W·m−1·K−1
Protons: 2 Thermal Expansion: N/A
Neutrons: 2 Electrical Resistivity: N/A
Electron Configuration: 1s2 Electronegativity: N/A
Atomic Radius: N/A Tensile Strength: N/A
Covalent Radius: 28 pm Molar Heat Capacity: 5R/2 = 20.786 J·mol−1·K−1
Van der Waals radius: 140 pm Young's Modulus: N/A
Oxidation States: 0 Shear Modulus: N/A
Phase: Gas Bulk Modulus: N/A
Crystal Structure: hexagonal close-packed Poisson Ratio: N/A
Magnetic Ordering: diamagnetic Mohs Hardness: N/A
1st Ionization Energy: 2372.3 kJ·mol−1 Vickers Hardness: N/A
2nd Ionization Energy: 5250.5 kJ·mol−1 Brinell Hardness: N/A
3rd Ionization Energy: N/A Speed of Sound: 972 m·s−1
       
IDENTIFIERS   MISCELLANEOUS  
CAS Number: 7440-59-7 Abundance in typical human body, by weight: N/A
ChemSpider ID: 22423 Abundance in typical human body, by atom: N/A
PubChem CID: 23987 Abundance in universe, by weight: 230000000 ppb
MDL Number: MFCD00011031 Abundance in universe, by atom: 72000000 ppb
EC Number: 231-168-5 Discovered By: Pierre Janssen, Norman Lockyer
Beilstein Number: N/A Discovery Date: 1868
SMILES Identifier: [He]  
InChI Identifier: InChI=1S/He Other Names: Elio, Hélio
InChI Key: SWQJXJOGLNCZEY-UHFFFAOYSA-N  
       
       
       
       
       


Recent Research & Development for Helium

  • X. Xiang, C.A. Chen, K.Z. Liu, X.L. Wang, X.C. Lai, Effect of combined doping of Fe and C on the helium behavior in Al before and after aging, Journal of Nuclear Materials, Volume 455, Issues 1–3, December 2014
  • Xuebang Wu, Xiang-Shan Kong, Yu-Wei You, C.S. Liu, Q.F. Fang, Jun-Ling Chen, G.-N. Luo, Zhiguang Wang, First principles study of helium trapping by solute elements in tungsten, Journal of Nuclear Materials, Volume 455, Issues 1–3, December 2014
  • Kotaro Ono, Mitsutaka Miyamoto, Kazuto Arakawa, Shin-ichi Matsumoto, Fumiaki Kudo, Effects of precipitated helium, deuterium or alloy elements on glissile motion of dislocation loops in Fe–9Cr–2W ferritic alloy, Journal of Nuclear Materials, Volume 455, Issues 1–3, December 2014
  • R.E. Stoller, Yu.N. Osetsky, An atomistic assessment of helium behavior in iron, Journal of Nuclear Materials, Volume 455, Issues 1–3, December 2014
  • M. Klimenkov, A. Möslang, E. Materna-Morris, Helium influence on the microstructure and swelling of 9%Cr ferritic steel after neutron irradiation to 16.3 dpa, Journal of Nuclear Materials, Volume 453, Issues 1–3, October 2014
  • Jinchao Zhang, Chun Cheng, Erdong Wu, Liangyin Xiong, Shi Liu, Thermal evolution of helium in magnetron sputtered titanium films, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Volume 336, 1 October 2014
  • Jun Cai, Daogang Lu, The formation energy and bonding characteristics of small helium–vacancy clusters on the low-index surface of a-Fe by first principles calculations, Computational Materials Science, Volume 92, September 2014
  • Lyudmila Chekushina, Daulet Dyussambaev, Asset Shaimerdenov, Kunihiko Tsuchiya, Tomoaki Takeuchi, Hiroshi Kawamura, Timur Kulsartov, Properties of tritium/helium release from hot isostatic pressed beryllium of various trademarks, Journal of Nuclear Materials, Volume 452, Issues 1–3, September 2014
  • N.J. Dutta, N. Buzarbaruah, S.R. Mohanty, Damage studies on tungsten due to helium ion irradiation, Journal of Nuclear Materials, Volume 452, Issues 1–3, September 2014
  • Thomas Danielson, Celine Hin, Structural and electronic effects of helium interstitials in Y2Ti2O7: A first-principles study, Journal of Nuclear Materials, Volume 452, Issues 1–3, September 2014
  • G. Gutierrez, S. Peuget, J.A. Hinks, G. Greaves, S.E. Donnelly, E. Oliviero, C. Jégou, Helium bubble formation in nuclear glass by in-situ TEM ion implantation, Journal of Nuclear Materials, Volume 452, Issues 1–3, September 2014
  • B.L. Zhang, X.Y. Song, J. Wang, Q. Hou, Molecular dynamics study on the effect of interaction potentials on the pressures of high density helium, Solid State Communications, Volume 193, September 2014
  • Q. Xu, Y. Sugiura, X.Q. Pan, K. Sato, T. Yoshiie, Effects of dislocation-trapped helium on mechanical properties of Fe, Materials Science and Engineering: A, Volume 612, 26 August 2014
  • Peri Landau, Qiang Guo, Peter Hosemann, Yongqiang Wang, Julia R. Greer, Deformation of as-fabricated and helium implanted 100 nm-diameter iron nano-pillars, Materials Science and Engineering: A, Volume 612, 26 August 2014
  • C.H. Chen, H. Niu, D.C. Yan, H.H. Hsieh, R.T. Huang, C.C. Chi, C.P. Lee, Local structure and magnetic properties of ferromagnetic GaMnAs made by helium ion induced epitaxial crystallization annealing, Applied Surface Science, Volume 310, 15 August 2014
  • Fangshu Liu, Haitao Ren, Shixiang Peng, Kaigui Zhu, Effect of crystal orientation on low flux helium and hydrogen ion irradiation in polycrystalline tungsten, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Volume 333, 15 August 2014
  • Xiao-Chun Li, Yi-Nan Liu, Yi Yu, Guang-Nan Luo, Xiaolin Shu, Guang-Hong Lu, Helium defects interactions and mechanism of helium bubble growth in tungsten: A molecular dynamics simulation, Journal of Nuclear Materials, Volume 451, Issues 1–3, August 2014
  • Wataru Kada, Takahiro Satoh, Akihito Yokoyama, Masashi Koka, Tomihiro Kamiya, Simultaneous ion luminescence imaging and spectroscopy of individual aerosol particles with external proton or helium microbeams, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Volume 332, 1 August 2014
  • C.P. Xu, X.-Y. Liu, F. Gao, Y.H. Li, Y.Q. Wang, Modeling radiation damage near grain boundary in helium-doped a-iron, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Volume 332, 1 August 2014
  • Lin Hu, Karl D. Hammond, Brian D. Wirth, Dimitrios Maroudas, Dynamics of small mobile helium clusters near tungsten surfaces, Surface Science, Volume 626, August 2014

Helium Isotopes


Helium has two stable isotopes: 3He and 4He.

Nuclide Symbol Isotopic Mass Half-Life Nuclear Spin
3He 3.0160293191 Stable 1/2+
4He 4.0026032542 Stable 0+