Helium (He)
grundstof med atomnummer 2
| Atomnummer | 2 |
|---|---|
| Atommasse | 4.002602 |
| mass number | 4 |
| Gruppe | 18 |
|---|---|
| Periode | 1 |
| Blok | s |
| proton | 2 p+ |
|---|---|
| neutron | 2 n0 |
| elektron | 2 e- |
Fysisk Egenskab
| Atomradius | |
|---|---|
| molar volume | |
| Kovalent Radius | |
| Metallic Radius | |
| Ionisk radius | |
| Crystal Radius | |
| Van der Waals-radius | |
| massefylde |
Kemisk Egenskab
| energi | |
|---|---|
| proton affinity | |
| electron affinity | |
| ioniseringsenergi | |
| Fordampningsvarme | |
| smeltevarme | |
| standard enthalpy of formation | |
| elektron | |
| Elektronskal | 2 |
 | |
| Valenselektron | 2 ⓘ |
 | |
| electron configuration | 1s2ⓘ |
  | |
| Oxidationstrin | |
| Elektronegativitet | |
| Electrophilicity Index | |
| fundamental state of matter | |
| stoffase | Gas |
| gaseous state of matter | Monoatomic |
| Kogepunkt | |
| Smeltepunkt | |
| critical pressure | |
| critical temperature | |
| trippelpunkt | |
| appearance | |
| farve | Colorless
|
| appearance | colorless gas, exhibiting a red-orange glow when placed in a high-voltage electric field |
| Brydningsindeks | 1,000035
|
| materialeegenskab | |
| Varmeledningsevne | |
| Termisk ekspansion | |
| molar heat capacity | |
| Varmefylde | |
| Adiabateksponenten | 5/3 |
| electrical properties | |
| type | |
| specifik ledningsevne | |
| Elektrisk resistivitet | |
| superledning | |
| Magnetisme | |
| type | diamagnetic |
| magnetic susceptibility (Mass) | -0,0000000059 m³/Kg
|
| magnetic susceptibility (Molar) | -0,0000000000236 m³/mol
|
| magnetic susceptibility (Volume) | -0,00000000105
|
| magnetic ordering | |
| Curietemperaturen | |
| Néel temperature | |
| struktur | |
| Krystalstruktur | Fladecentreret Kubisk (HEX) |
| lattice constant | |
| Lattice Angles | π/2, π/2, π/2 |
| mechanical property | |
| hårdhed | |
| Kompressibilitetsmodul | |
| Forskydningsmodul | |
| E-modul | |
| Poissons forhold | |
| speed of sound | |
| klassificering | |
| Kategori | Ædelgasser, Noble gases |
| CAS Group | VIII |
| IUPAC Group | VIIIA |
| Glawe Number | 1 |
| Mendeleev Number | 112 |
| Pettifor Number | 1 |
| Geochemical Class | volatile |
| Goldschmidt classification | atmophile |
øvrige
| Gas Basicity | |
|---|---|
| polarizability | |
| C6 Dispersion Coefficient | |
| allotrope | |
| Neutron cross section | 0,007
|
| Neutron Mass Absorption | 0,00001
|
| quantum number | 1S0 |
| rumgruppe | 225 (Fm_3m) |
Isotopes of Helium
| Stable Isotopes | 2 |
|---|---|
| Unstable Isotopes | 6 |
| Natural Isotopes | 2 |
3He
| mass number | 3 |
|---|---|
| neutron number | 1 |
| Relative Atomic Mass | |
| g-factor | -4,25525062 ± 0,00000006
|
| natural abundance | 0,0002 ± 0,0002
|
| radioaktivitet | stable isotope |
| halveringstid | Not Radioactive ☢️ |
| spin | 1/2 |
| nuclear quadrupole moment | 0
|
| opdagelsesdato | 1934 |
| Paritet | + |
4He
| mass number | 4 |
|---|---|
| neutron number | 2 |
| Relative Atomic Mass | |
| g-factor | 0
|
| natural abundance | 99,9998 ± 0,0002
|
| radioaktivitet | stable isotope |
| halveringstid | Not Radioactive ☢️ |
| spin | 0 |
| nuclear quadrupole moment | 0
|
| opdagelsesdato | 1908 |
| Paritet | + |
5He
| mass number | 5 |
|---|---|
| neutron number | 3 |
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivitet | ☢️ radioactive element |
| halveringstid | 602 ± 22 ys
|
| spin | 3/2 |
| nuclear quadrupole moment | |
| opdagelsesdato | 1937 |
| Paritet | - |
| decay mode | Intensitet |
|---|---|
| n (neutron emission) | 100% |
6He
| mass number | 6 |
|---|---|
| neutron number | 4 |
| Relative Atomic Mass | |
| g-factor | 0
|
| natural abundance | |
| radioaktivitet | ☢️ radioactive element |
| halveringstid | 806,92 ± 0,24 ms
|
| spin | 0 |
| nuclear quadrupole moment | 0
|
| opdagelsesdato | 1936 |
| Paritet | + |
| decay mode | Intensitet |
|---|---|
| β− (β− decay) | 100% |
| β− d (β−-delayed deuteron emission) | 0.000278% |
7He
| mass number | 7 |
|---|---|
| neutron number | 5 |
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivitet | ☢️ radioactive element |
| halveringstid | 2,51 ± 0,07 zs
|
| spin | 3/2 |
| nuclear quadrupole moment | |
| opdagelsesdato | 1967 |
| Paritet |
| decay mode | Intensitet |
|---|---|
| n (neutron emission) | 100% |
8He
| mass number | 8 |
|---|---|
| neutron number | 6 |
| Relative Atomic Mass | |
| g-factor | 0
|
| natural abundance | |
| radioaktivitet | ☢️ radioactive element |
| halveringstid | 119,5 ± 1,5 ms
|
| spin | 0 |
| nuclear quadrupole moment | 0
|
| opdagelsesdato | 1965 |
| Paritet | + |
| decay mode | Intensitet |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 16% |
| β− t (β−-delayed triton emission) | 0.9% |
9He
| mass number | 9 |
|---|---|
| neutron number | 7 |
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivitet | ☢️ radioactive element |
| halveringstid | 2,5 ± 2,3 zs
|
| spin | 1/2 |
| nuclear quadrupole moment | 0
|
| opdagelsesdato | 1987 |
| Paritet |
| decay mode | Intensitet |
|---|---|
| n (neutron emission) | 100% |
10He
| mass number | 10 |
|---|---|
| neutron number | 8 |
| Relative Atomic Mass | |
| g-factor | 0
|
| natural abundance | |
| radioaktivitet | ☢️ radioactive element |
| halveringstid | 260 ± 40 ys
|
| spin | 0 |
| nuclear quadrupole moment | 0
|
| opdagelsesdato | 1994 |
| Paritet | + |
| decay mode | Intensitet |
|---|---|
| 2n (2-neutron emission) | 100% |
historie
| opdager eller opfinder | Sir William Ramsey, Nils Langet, P.T.Cleve |
|---|---|
| fundsted | Scotland/Sweden |
| opdagelsesdato | 1895 |
| etymologi | Greek: hêlios (sun). |
| udtale | HEE-li-em (engelsk) |
source
| Forekomst | |
|---|---|
| Abundance in Earth's crust | |
| natural abundance (verdenshave) | |
| natural abundance (menneskelige krop) | |
| natural abundance (Meteoroid) | |
| natural abundance (Solen) | 23 %
|
| Abundance in Universe | 23 %
|
Nuclear Screening Constants
| 1 | s | 0.3125 |
