helium 4 | has symbol 4He | |
has natural abundance 99.999863 % | |
has nuclear magnetic moment μ = 0 | |
has nuclear spin I = 0+ | |
has number of nucleons 4 | |
has number of neutrons 2 | |
has atomic mass 4.00260324 | |
is an instance of helium | |
helium | has stable isotope helium 3, helium 4 | |
has lethal intake non-toxic | |
has reserves 3.7 × 109 tonnes in Earth's atmosphere | |
has mineral present in some minerals | |
has neutron scattering length 0.326 × 10-12 cm | |
has electron affinity 0.0 kJ mol-1 from to - | |
has toxic intake non-toxic | |
has mass magnetic susceptibility -5.9 × 10-9 kg-1 m3 for gas | |
has van der Waals radii 120 pm | |
has thermal neutron capture cross section 0.007 barns | |
has longest lived isotope helium 4 | |
has isotope mass range 3 to 8 except 7 | |
has number of isotopes 5 including nuclear isomers | |
has pronunciation heel-iuhm | |
has name origin helios = sun from Greek | |
has discovery location England | |
has abundance 6.31 × 1010 in Sun relative to H = 1 × 1012 | |
has abundance 0.008 p.p.m. in Earth's crust | |
has abundance 5.2 p.p.m. by volume in Earth's atmosphere | |
has abundance 4 × 10-6 p.p.m. in seawater | |
has specimen small pressurized canisters. Safe. | |
has world production 4500 tonnes year-1 | |
has chief source natural gas which may contain up to 7% helium | |
has mass absorption coefficient 0.383 cm2 g-1 for CuKα X-ray diffraction | |
has mass absorption coefficient 0.207 cm2 g-1 for MoKα X-ray diffraction | |
has space group P63/mmc for α-He at 1.15 K, 6.69 MPa | |
has space group Fm3m for β-He at 16K, 127 MPa | |
has space group Im3m for γ-He at 1.73 K, 2.94 MPa | |
has crystal cell dimension a = 353.1, c = 569.3 pm for α-He at 1.15 K, 6.69 MPa | |
has crystal cell dimension a = 424.0 pm for β-He at 16K, 127 MPa | |
has crystal cell dimension a = 411 pm for γ-He at 1.73 K, 2.94 MPa | |
has crystal type h.c.p. for α-He at 1.15 K, 6.69 MPa | |
has crystal type f.c.c. for β-He at 16K, 127 MPa | |
has crystal type b.c.c. for γ-He at 1.73 K, 2.94 MPa | |
has atomic emission line 388.865 nm for He I | |
has atomic emission line 587.562 nm for He I | |
has atomic emission line 1083.025 nm for He I | |
has atomic emission line 1083.034 nm for He I (strong) | |
has atomic emission line 1868.534 nm for He I | |
has atomic emission line 2058.130 nm for He I | |
has term symbol 1S0 in ground state | |
has electron configuration 1s2 = [He] in ground state | |
has mass of element in person very small for a 70 kg average person | |
has daily dietary intake very low | |
has level in humans traces | |
has hazard harmless but could asphyxiate if it excludes oxygen from the lungs | |
has biological role none | |
has thermal conductivity 0.152 W m-1 K-1 at 300 K | |
has molar volume 32.07 cm3 at 4 K | |
has heat capacity 20.786 J K-1 mol-1 for gas at constant pressure 0.1 MPa at 298.15 K | |
has heat of vaporization 0.082 kJ mol-1 | |
has heat of fusion 0.021 kJ mol-1 | |
has boiling point 4.216 K | |
has melting point 0.95 K under pressure | |
has relative atomic mass 4.005602 in units of 12C = 12.000 | |
has atomic radii 128 pm | |
has number of protons 2 | |
has registry number 7440-59-7 for Chemical Abstracts System database | |
has density 124.8 kg m-3 for liquid at 4.216 K boiling point | |
has density 0.1785 kg m-3 for gas at 273 K | |
has synthesis mechanism | |
has ocean oxidation state 0 | |
has atomic number 2 | |
reacts with nothing | |
has discovery date 1868 | |
has discoverer Norman Lockyer and Edward Frankland | |
has uses deep-sea diving, weather baloons, low temperature research | |
has image | |
has critical pressure 229 kPa | |
has critical temperature 5.25 K | |
unclassified oceanic element | has ocean residence time unknown | |
has ocean concentration unknown | |
inert gas | has group 18 | |
has synonym group VIII element | |
has synonym noble gas | |
element | is a part of Universe | |
oceanic element | has occurrence ocean | |
atmophile element | has occurrence atmosphere of a planet or asteroid | |
gaseous element | has state gas at standard temperature and pressure | |
particle | obeys uncertainty principle | |
has frequency inversely proportional to the wavelength | |
has wavelength inversely proportional to its momentum | |
has charge | |
has mass | |
physical object | has location or center of gravity | |
has angular momentum | |
has velocity | |
has momentum | |
has temperature | |
has volume | |
has extent | |
has material | |