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Atomic: M.A.C. | Reference
Diagrams: Shell | Atomic Radius | Electron || Images
Hydrogen
Electrons per shell 1
Electron Configuration 1s1 open electron config
Ground state 2S1/2
Atomic Volume 14.4 cm3 mol-1
Electronegativity 2.20
Magnetic ordering No data
Mass magnetic susceptibility -2.48 x 10-8
Molar magnetic susceptibility -2.5 x 10-11
Speed of sound 1310 m s-1
Thermal Properties
Enthalpy of Atomization 217.6 kJ mol-1 @25°C
Enthalpy of Fusion 0.12 kJ mol-1
Enthalpy of Vaporisation 0.46 kJ mol-1
Heat Capacity 28.836 (H2) J mol-1 K-1
Thermal Conductivity 180.5 W m-1 K-1
Thermal Expansion No data.
Electrical Properties
Electrical resistivity No data.
Electrical conductivity ? 106/cm Ω
Chemical Properties
Electrochemical Equivalent 0.037605 g Ah-1
Valence Electron Potential (-eV) 1200
Ionization Potential  
First 13.598
Incompatibilities Metals, oxidizing materials, metal oxides, combustible materials, halogens, metal salts, halo carbons.
Flammability
Highly flammable gas
Autoignition temp 773K (500°C)
Flashpoint 20K (-253°C) Theoretical
Optical Properties
Refractive Index (gas) 1.000132
Refractive Index (liquid) 1.12
Energy Levels
Kα1 (intensity 100) 0.012 KeV
Atomic Radii
Empirical 25 pm
Bohr Radius 53 pm
Covalent Radius 37 pm
Van der Waals 120 pm
Triple covalent No data.
Metallic No data.
Oxidation States
Main H+1
Other H0, H-1
Ionisation Energies (kJ mol-1) show graph
M - M+ 1312
Covalent Bonds (kJ mol-1)
H-H 454
H-F 566
H-Cl 431
H-Br 366
H-I 299
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 15 20
Crystal Structure
Structure Hexagonal close packed
a = 470 pm
b = 470 pm
c = 340 pm
α = 90°
β = 90°
γ = 120°