The periodic Table
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by Peder Axensten

H


in WebElements
in X-Ray info 		H, 1
hydrogen (English)
hydrogène, m. (French)
Wasserstoff, m. (German)
vodorod (Russian)
hidrógeno (Spanish)
väte (Swedish)

Symbol, numberH, 1 (non-metal), Group: 1; 1A
Weight1.00794
In NatureHydrogen is the most abundant element in the universe, 90% of the universe's weight consists of hydrogen.
Discovered1766, by G. Kavendish (England)
Nameof Greek hydro genes, maker of water
Density  [kg/m3]76.0 [11 K] (solid)   70.8 [20 K] (liquid)   0.08988 [273 K] (gas)   
Molar volume11.42 cm3
Speed of sound1270 m/s
Critical Temperature33.2 K   (-239.8 °C)
Melting Temperature14.01 K   (-258.99 °C)   Enthalpy: 0.46 kJ/mol
Boiling Temperature20.28 K   (-252.72 °C)   Enthalpy: 0.12 kJ/mol
Atomizing218 kJ/mol
Optics1.000132 gas, 1.12 liquid (refraction)
Specific heat14300
Heat fusion116.300
ThermalConductivity: 0.1815 [300 K] (gas) W/Km     
Configuration1s1
Crystal structurehcp (hexagonal close-packed)
Spectral lines [nm]434.047 I, 486.133 I, 656.272 I, 656.285 I, 1875.10 I
Ionisation [kJ/mol]
  M-->  M+--> M2+--> M3+--> M4+--> M5+--> M6+--> M7+--> M8+--> M9+-->M10+
1312.0
Thermodynamics
State DfH° DfG° S° CpH H°298.15-H°0
[kJ/mol] [J/Kmol] [kJ/mol]
gas (H2) 0 130.680±0.003 28.82 8.468±0.001
gas (H) 217.998±0.006 203.26 114.717±0.002 20.786 6.197±0.001
gas (2H) 221.67 206.52 123.24 20.786 6.20
gas (2H2; D2) 0 144.85 29.20 8.569
gas (H2H; HD) 0.33 -1.46 143.69 29.20 8.505
Isotopes
Mass In nature Half-life Spin m/mN NMM Decay
1H 1.007825035 99.9885% stable 1/2 2.7928456
2H 2.014101779 0.0115% stable 1 0.8574376
3H 3.01604927 12.32 y 1/2 2.978960 β- to 3He
4H n to 3H
5H n to 4H
6H n to 5H