Helium

Helium (He)

chemical element with symbol He and atomic number 2; rare gas
Atomic Number2
Atomic Weight4.002602
mass number4
Group18
Period1
Blocks
Proton2 p+
Neutron2 n0
Elektron2 e-
Animated Bohr model of He (Helium)

Physikalesch Eegenschaft

Atomic Radius
molar volume
Covalent Radius
Metallic Radius
ionic radius
Crystal Radius
Van der Waals radius
density
Atomic Radii Of The Elements: Helium0102030405060708090100110120130140pmAtomic RadiusCovalent RadiusMetallic RadiusVan der Waals radius

Chemical Property

energie
proton affinity
electron affinity
ionization energy
ionization energy of He (Helium)
enthalpy of vaporization
enthalpy of fusion
standard enthalpy of formation
Elektron
electron shell2
Bohr model: He (Helium)
valence electron2
Lewis structure: He (Helium)
electron configuration1s2
Enhanced Bohr model of He (Helium)
Orbital Diagram of He (Helium)
oxidation number
electronegativity
Electrophilicity Index
fundamental state of matter
phase of matterGas
gaseous state of matterMonoatomic
Boiling Point
Melting Point
critical pressure
critical temperature
triple point
appearance
Faarf
Colorless
appearancecolorless gas, exhibiting a red-orange glow when placed in a high-voltage electric field
refractive index
1,000035
thermodynamic material property
Thermal Conductivity
thermal expansion
molar heat capacity
Specific Heat Capacity
heat capacity ratio5/3
electrical properties
type
electrical conductivity
electrical resistivity
superconductivity
Magnetismus
typediamagnetic
magnetic susceptibility (Mass)
-0,0000000059 m³/Kg
magnetic susceptibility (Molar)
-0,0000000000236 m³/mol
magnetic susceptibility (Volume)
-0,00000000105
magnetic ordering
Curie temperature
Néel temperature
Struktur
Crystal StructureFace Centered Cubic (HEX)
lattice constant
Lattice Anglesπ/2, π/2, π/2
mechanical property
hardness
bulk modulus
shear modulus
Young's modulus
Poisson's ratio
speed of sound
classification
CategoryNoble gases, Noble gases
CAS GroupVIII
IUPAC GroupVIIIA
Glawe Number1
Mendeleev Number112
Pettifor Number1
Geochemical Classvolatile
Goldschmidt classificationatmophile

other

Gas Basicity
polarizability
C6 Dispersion Coefficient
allotrope
Neutron cross section
0,007
Neutron Mass Absorption
0,00001
quantum number1S0
space group225 (Fm_3m)

Isotopes of Helium

Stable Isotopes2
Unstable Isotopes6
Natural Isotopes2
Isotopic Composition4100.00%4100.00%30.00%30.00%

3He

mass number3
neutron number1
Relative Atomic Mass
g-factor
-4,25525062 ± 0,00000006
natural abundance
0,0002 ± 0,0002
Radioaktivitéitstable isotope
half-lifeNot Radioactive ☢️
spin1/2
nuclear quadrupole moment
0
Datum vun der Entdeckung1934
parity+

4He

mass number4
neutron number2
Relative Atomic Mass
g-factor
0
natural abundance
99,9998 ± 0,0002
Radioaktivitéitstable isotope
half-lifeNot Radioactive ☢️
spin0
nuclear quadrupole moment
0
Datum vun der Entdeckung1908
parity+

5He

mass number5
neutron number3
Relative Atomic Mass
g-factor
natural abundance
Radioaktivitéit☢️ radioactive element
half-life
602 ± 22 ys
spin3/2
nuclear quadrupole moment
Datum vun der Entdeckung1937
parity-

decay modeintensity
n (neutron emission)100%

6He

mass number6
neutron number4
Relative Atomic Mass
g-factor
0
natural abundance
Radioaktivitéit☢️ radioactive element
half-life
806,92 ± 0,24 ms
spin0
nuclear quadrupole moment
0
Datum vun der Entdeckung1936
parity+

decay modeintensity
β (β decay)100%
β d (β-delayed deuteron emission)0.000278%

7He

mass number7
neutron number5
Relative Atomic Mass
g-factor
natural abundance
Radioaktivitéit☢️ radioactive element
half-life
2,51 ± 0,07 zs
spin3/2
nuclear quadrupole moment
Datum vun der Entdeckung1967
parity

decay modeintensity
n (neutron emission)100%

8He

mass number8
neutron number6
Relative Atomic Mass
g-factor
0
natural abundance
Radioaktivitéit☢️ radioactive element
half-life
119,5 ± 1,5 ms
spin0
nuclear quadrupole moment
0
Datum vun der Entdeckung1965
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)16%
β t (β-delayed triton emission)0.9%

9He

mass number9
neutron number7
Relative Atomic Mass
g-factor
natural abundance
Radioaktivitéit☢️ radioactive element
half-life
2,5 ± 2,3 zs
spin1/2
nuclear quadrupole moment
0
Datum vun der Entdeckung1987
parity

decay modeintensity
n (neutron emission)100%

10He

mass number10
neutron number8
Relative Atomic Mass
g-factor
0
natural abundance
Radioaktivitéit☢️ radioactive element
half-life
260 ± 40 ys
spin0
nuclear quadrupole moment
0
Datum vun der Entdeckung1994
parity+

decay modeintensity
2n (2-neutron emission)100%
Helium discharge tube

Geschicht

Entdecker oder ErfinderSir William Ramsey, Nils Langet, P.T.Cleve
location of discoveryScotland/Sweden
Datum vun der Entdeckung1895
EtymologieGreek: hêlios (sun).
pronunciationHEE-li-em (Englesch)

Quell

Abundance
Abundance in Earth's crust
natural abundance (Ozean)
natural abundance (Mënschleche Kierper)
natural abundance (Meteoroid)
natural abundance (Sonn)
23 %
Abundance in Universe
23 %

Nuclear Screening Constants

1s0.3125