Гелий

Гелий (He)

chemical element with symbol He and atomic number 2; rare gas
Atomic Number2
Atomic Weight4.002602
mass number4
Group18
Period1
Blocks
Протон2 p+
Нейтрон2 n0
Электрон2 e-
Animated Bohr model of He (Гелий)

Physical Property

Атомдук Радиус
120 pm
molar volume
31,8 cm³/mol
covalent radius
46 pm
Metallic Radius
ionic radius
Crystal Radius
Van der Waals radius
140 pm
density
0,000164 g/cm³
Atomic Radii Of The Elements: Гелий0102030405060708090100110120130140pmАтомдук РадиусCovalent RadiusMetallic RadiusVan der Waals radius

Chemical Property

энергия
proton affinity
177,8 kJ/mol
electron affinity
-19,7 eV/particle
ionization energy
24,587387936 eV/particle
ionization energy of He (Гелий)
enthalpy of vaporization
0,08 kJ/mol
enthalpy of fusion
standard enthalpy of formation
Электрон
electron shell2
Bohr model: He (Гелий)
valence electron2 ⓘ
Lewis structure: He (Гелий)
electron configuration1s2ⓘ
Enhanced Bohr model of He (Гелий)
Orbital Diagram of He (Гелий)
oxidation number
electronegativity
Electrophilicity Index
0,0674191963846371 eV/particle
fundamental state of matter
phase of matterGas
gaseous state of matterMonoatomic
Boiling Point
4,222 K
Melting Point
critical pressure
0,22746 MPa
critical temperature
5,195 K
triple point
2,177 K
5,043 kPa
appearance
Түс –
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
0,152 W/(m K)
thermal expansion
molar heat capacity
20,786 J/(mol K)
Specific Heat Capacity
5,193 J/(g⋅K)
heat capacity ratio5/3
electrical properties
type
electrical conductivity
electrical resistivity
superconductivity
Магнетизм
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
түзүм
Crystal StructureFace Centered Cubic (HEX)
lattice constant
3,57 Å
Lattice Anglesπ/2, π/2, π/2
mechanical property
hardness
bulk modulus
shear modulus
Young's modulus
Poisson's ratio
speed of sound
970 m/s
classification
CategoryNoble gases, Noble gases
CAS GroupVIII
IUPAC GroupVIIIA
Glawe Number1
Mendeleev Number112
Pettifor Number1
Geochemical Classvolatile
Литофиль элементтериatmophile

other

Gas Basicity
148,5 kJ/mol
polarizability
1,38375 ± 0,00002 a₀
C6 Dispersion Coefficient
1,42 a₀
allotrope
Neutron cross section
0,007
Neutron Mass Absorption
0,00001
Кванттык сандар1S0
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
3,01602932197 ± 0,00000000006 Da
g-factor
-4,25525062 ± 0,00000006
natural abundance
0,0002 ± 0,0002
Радиоактивдүүлүкstable isotope
half-lifeNot Radioactive ☢️
Спин1/2
nuclear quadrupole moment
0
time of discovery or invention1934
parity+

4He

mass number4
neutron number2
relative atomic mass
4,00260325413 ± 0,00000000016 Da
g-factor
0
natural abundance
99,9998 ± 0,0002
Радиоактивдүүлүкstable isotope
half-lifeNot Radioactive ☢️
Спин0
nuclear quadrupole moment
0
time of discovery or invention1908
parity+

5He

mass number5
neutron number3
relative atomic mass
5,012057224 ± 0,00002147 Da
g-factor
natural abundance
Радиоактивдүүлүк☢️ Радиоактивдүү элементтер —
half-life
602 ± 22 ys
Спин3/2
nuclear quadrupole moment
time of discovery or invention1937
parity-
decay modeintensity
n (neutron emission)100%

6He

mass number6
neutron number4
relative atomic mass
6,018885889 ± 0,000000057 Da
g-factor
0
natural abundance
Радиоактивдүүлүк☢️ Радиоактивдүү элементтер —
half-life
806,92 ± 0,24 ms
Спин0
nuclear quadrupole moment
0
time of discovery or invention1936
parity+
decay modeintensity
β− (β− decay)100%
β− d (β−-delayed deuteron emission)0.000278%

7He

mass number7
neutron number5
relative atomic mass
7,027990652 ± 0,000008115 Da
g-factor
natural abundance
Радиоактивдүүлүк☢️ Радиоактивдүү элементтер —
half-life
2,51 ± 0,07 zs
Спин3/2
nuclear quadrupole moment
time of discovery or invention1967
parity
decay modeintensity
n (neutron emission)100%

8He

mass number8
neutron number6
relative atomic mass
8,033934388 ± 0,000000095 Da
g-factor
0
natural abundance
Радиоактивдүүлүк☢️ Радиоактивдүү элементтер —
half-life
119,5 ± 1,5 ms
Спин0
nuclear quadrupole moment
0
time of discovery or invention1965
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
9,043946414 ± 0,000050259 Da
g-factor
natural abundance
Радиоактивдүүлүк☢️ Радиоактивдүү элементтер —
half-life
2,5 ± 2,3 zs
Спин1/2
nuclear quadrupole moment
0
time of discovery or invention1987
parity
decay modeintensity
n (neutron emission)100%

10He

mass number10
neutron number8
relative atomic mass
10,052815306 ± 0,000099676 Da
g-factor
0
natural abundance
Радиоактивдүүлүк☢️ Радиоактивдүү элементтер —
half-life
260 ± 40 ys
Спин0
nuclear quadrupole moment
0
time of discovery or invention1994
parity+
decay modeintensity
2n (2-neutron emission)100%
Helium discharge tube

тарых

discoverer or inventorSir William Ramsey, Nils Langet, P.T.Cleve
location of discoveryScotland/Sweden
time of discovery or invention1895
ЭтимологияGreek: hêlios (sun).
pronunciationHEE-li-em (англисче)

source

Abundance
Abundance in Earth's crust
0,008 mg/kg
natural abundance (Океан)
0,000007 mg/L
natural abundance (human body)
natural abundance (meteoroid)
natural abundance (Күн)
23 %
Abundance in Universe
23 %

Nuclear Screening Constants

1s0.3125
Гелий on ChemicalAid