હીલિયમ

હીલિયમ (He)

chemical element with symbol He and atomic number 2; rare gas
Atomic Number2
Atomic Weight4.002602
mass number4
Group18
Period1
Blocks
પ્રોટોન2 p+
neutron2 n0
ઈલેક્ટ્રોન2 e-
Animated બૉહરનો સિદ્ધાંત of He (હીલિયમ)

Physical Property

Atomic Radius
120 pm
molar volume
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: હીલિયમ0102030405060708090100110120130140pmAtomic RadiusCovalent RadiusMetallic RadiusVan der Waals radius

રાસાયણિક ગુણધર્મ

ઉર્જા
proton affinity
177.8 kJ/mol
electron affinity
ionization energy
24.587387936 eV/particle
ionization energy of He (હીલિયમ)
enthalpy of vaporization
0.08 kJ/mol
enthalpy of fusion
standard enthalpy of formation
ઈલેક્ટ્રોન
electron shell2
બૉહરનો સિદ્ધાંત: He (હીલિયમ)
valence electron2
Lewis structure: He (હીલિયમ)
electron configuration1s2
Enhanced બૉહરનો સિદ્ધાંત of He (હીલિયમ)
Orbital Diagram of He (હીલિયમ)
oxidation number
વિદ્યુતઋણતા
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
color
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
magnetism
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
structure
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
અવાજની ઝડપ
970 m/s
classification
CategoryNoble gases, Noble gases
CAS GroupVIII
IUPAC GroupVIIIA
Glawe Number1
Mendeleev Number112
Pettifor Number1
Geochemical Classvolatile
Goldschmidt classificationatmophile

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
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
3.01602932197 ± 0.00000000006 Da
g-factor
-4.25525062 ± 0.00000006
natural abundance
0.0002 ± 0.0002
radioactivitystable isotope
half-lifeNot Radioactive ☢️
પ્રચક્રણ1/2
nuclear quadrupole moment
0
શોધની તારીખ1934
પૅરિટી+

4He

mass number4
neutron number2
relative atomic mass
4.00260325413 ± 0.00000000016 Da
g-factor
0
natural abundance
99.9998 ± 0.0002
radioactivitystable isotope
half-lifeNot Radioactive ☢️
પ્રચક્રણ0
nuclear quadrupole moment
0
શોધની તારીખ1908
પૅરિટી+

5He

mass number5
neutron number3
relative atomic mass
5.012057224 ± 0.00002147 Da
g-factor
natural abundance
radioactivity☢️ radioactive element
half-life
602 ± 22 ys
પ્રચક્રણ3/2
nuclear quadrupole moment
શોધની તારીખ1937
પૅરિટી-

decay modeintensity
n (neutron emission)100%

6He

mass number6
neutron number4
relative atomic mass
6.018885889 ± 0.000000057 Da
g-factor
0
natural abundance
radioactivity☢️ radioactive element
half-life
806.92 ± 0.24 ms
પ્રચક્રણ0
nuclear quadrupole moment
0
શોધની તારીખ1936
પૅરિટી+

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
radioactivity☢️ radioactive element
half-life
2.51 ± 0.07 zs
પ્રચક્રણ3/2
nuclear quadrupole moment
શોધની તારીખ1967
પૅરિટી

decay modeintensity
n (neutron emission)100%

8He

mass number8
neutron number6
relative atomic mass
8.033934388 ± 0.000000095 Da
g-factor
0
natural abundance
radioactivity☢️ radioactive element
half-life
119.5 ± 1.5 ms
પ્રચક્રણ0
nuclear quadrupole moment
0
શોધની તારીખ1965
પૅરિટી+

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
radioactivity☢️ radioactive element
half-life
2.5 ± 2.3 zs
પ્રચક્રણ1/2
nuclear quadrupole moment
0
શોધની તારીખ1987
પૅરિટી

decay modeintensity
n (neutron emission)100%

10He

mass number10
neutron number8
relative atomic mass
10.052815306 ± 0.000099676 Da
g-factor
0
natural abundance
radioactivity☢️ radioactive element
half-life
260 ± 40 ys
પ્રચક્રણ0
nuclear quadrupole moment
0
શોધની તારીખ1994
પૅરિટી+

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

ઈતિહાસ

શોધક અથવા સંશોધકSir William Ramsey, Nils Langet, P.T.Cleve
શોધનું સ્થળScotland/Sweden
શોધની તારીખ1895
etymologyGreek: hêlios (sun).
ઉચ્ચારHEE-li-em (અંગ્રેજી)

source

Abundance
Abundance in Earth's crust
0.008 mg/kg
natural abundance (ocean)
0.000007 mg/L
natural abundance (માનવ શરીર)
natural abundance (ઉલ્કા)
natural abundance (સૂર્ય)
23 %
Abundance in Universe
23 %

Nuclear Screening Constants

1s0.3125