Template:Infobox helium

Helium, 2He
A clear tube with a red light emanating from it
Helium
Pronunciation/ˈhliəm/ (HEE-lee-əm)
Appearancecolorless gas, exhibiting a gray, cloudy glow (or reddish-orange if an especially high voltage is used) when placed in an electric field
Standard atomic weight Ar°(He)
Helium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


He

Ne
hydrogenheliumlithium
Atomic number (Z)2
Groupgroup 18 (noble gases)
Periodperiod 1
Block  s-block
Electron configuration1s2
Electrons per shell2
Physical properties
Phase at STPgas
Boiling point4.222 K ​(−268.928 °C, ​−452.070 °F)
Density (at STP)0.1786 g/L
when liquid (at b.p.)0.125 g/cm3
Triple point2.177 K, ​5.043 kPa
Critical point5.1953 K, 0.22746 MPa
Heat of fusion0.0138 kJ/mol
Heat of vaporization0.0829 kJ/mol
Molar heat capacity20.78 J/(mol·K)[3]
Vapor pressure (defined by ITS-90)
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K)     1.23 1.67 2.48 4.21
Atomic properties
Oxidation statescommon: (none)
ElectronegativityPauling scale: no data
Ionization energies
  • 1st: 2372.3 kJ/mol
  • 2nd: 5250.5 kJ/mol
Covalent radius28 pm
Van der Waals radius140 pm
Color lines in a spectral range
Spectral lines of helium
Other properties
Natural occurrenceprimordial
Crystal structurehexagonal close-packed (hcp)
Hexagonal close-packed crystal structure for helium
Thermal conductivity0.1513 W/(m⋅K)
Magnetic orderingdiamagnetic[4]
Molar magnetic susceptibility−1.88×10−6 cm3/mol (298 K)[5]
Speed of sound972 m/s
CAS Number7440-59-7
History
Namingafter Helios, Greek god of the Sun
DiscoveryNorman Lockyer (1868)
First isolationWilliam Ramsay, Per Teodor Cleve, Abraham Langlet (1895)
Isotopes of helium
Main isotopes[6] Decay
abun­dance half-life (t1/2) mode pro­duct
3He 0.0002%
Preview warning: Infobox He isotopes: Abundance percentage not recognised "na=0.0002%" cat#%
stable
4He 99.9998%
Preview warning: Infobox He isotopes: Abundance percentage not recognised "na=99.9998%" cat#%
stable
 Category: Helium
| references
He · Helium
H ←

ibox H

iso
2
He  [e]
IB-He [e]
IBisos [e]
→ Li

ibox Li

indexes by PT (page)
child table, as reused in {IB-He}
Main isotopes of helium
Main isotopes[6] Decay
abun­dance half-life (t1/2) mode pro­duct
3He 0.0002%
Preview warning: Infobox He isotopes: Abundance percentage not recognised "na=0.0002%" cat#%
stable
4He 99.9998%
Preview warning: Infobox He isotopes: Abundance percentage not recognised "na=99.9998%" cat#%
stable
Data sets read by {{Infobox element}}
Name and identifiers
Symbol etymology (11 non-trivial)
Top image (caption, alt)
Pronunciation
Allotropes (overview)
Group (overview)
Period (overview)
Block (overview)
Natural occurrence
Phase at STP
Oxidation states
Spectral lines image
Electron configuration (cmt, ref)
Isotopes
Standard atomic weight
  most stable isotope
Wikidata
Wikidata *
* Not used in {{Infobox element}} (2023-01-01)
See also {{Index of data sets}} · Cat:data sets (46) · (this table: )

References

  1. ^ "Standard Atomic Weights: Helium". CIAAW. 1983.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  3. ^ Shuen-Chen Hwang, Robert D. Lein, Daniel A. Morgan (2005). "Noble Gases". Kirk Othmer Encyclopedia of Chemical Technology. Wiley. pp. 343–383. doi:10.1002/0471238961.0701190508230114.a01.
  4. ^ Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.
  5. ^ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  6. ^ a b Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

One of these is a named reference. It may be cited in the containing article as

  • <ref name = "CIAAW2013" /> for the source Atomic weights of the elements 2013 (from subtemplates used by {{Infobox element}})