 | Helium | Atomic Number: 2 |
- Overview
Property Value Units 4.0026
0.1785
- Thermal Properties
Thermal Properties
Property Value Units -272°C
-269°C
0.227 MPa
5.19°C
0.02 kJ/mol
0.083 kJ/mol
5193.1 J/kg·K
0.1513 W/m·K
- Electon Configuration
1s2
K L M N O P Q 2 0 0 0 0 0 0 Level S Orbital P Orbital D Orbital F Orbital Level 1 Level 2 - History
Year Discovered
1895
- Isotopes
Isotope Common Name Symbol Mass Status Abundance Half-life Decay mode Decay Energy Nuclear Spin Magnetic Moment 2
He
3
Helium He 3 Stable 0.000137 - - - 0.5 -2.12762485 2
He
4
Helium He 4 Stable 99.999863 - - - 0 0 2
He
5
Helium He 5 
0 .0000000000007 n n 0.89 1.5 0 2
He
6
Helium He 6 0 806.7 ms B- 3.508313 0 0 2
He
7
Helium He 7 0 .0000000000029 n n 0.4346 1.5 0 2
He
8
Helium He 8 0 119 ms B-, B-n, B-t 10.6512 0 0 2
He
9
Helium He 9 0 .000000000007 ns n 1.2701 0.5 0 2
He
10
Helium He 10 0 .0000000000027 n 2n 1.0685 0 0 Isotopic mass data for stable isotopes is from:
G. Audi, A.H. Wapstra in Nuclear Physics A, 1993, 565, 1-65
and
G. Audi, A.H.Wapstra in Nuclear Physics A, 1995, 595 409-480.Natural abundance data is from:
K.J.R. Rosman, P.D.P. Taylor in Pure Appplied Chemistry, 1999, 71, 1593-1607.- Occurance
In the Universe 23% In the Sun 23% In Meteorites 0% In the Earth's Crust 0.00000055% In Seawater 7.2E-10% In the Human Body 0% - Models
Pictures, videos and 3D models of the element
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