Hydrogen

Hydrogen Element Properties

s1
H
Hydrogen
s2
He
Helium
General
NameHydrogen
SymbolH
Number1
Group Number1
GroupNon-Metal
Blocks
Density0.0000899 g/cm3
Atomic Weight1.00794 g/mol
Atomic Volume14.4 cm3/mol
Discover1766


States
StateGas
Melting Point14.01 K
Boiling Point20.28 K
Triple Point13.8033 K
Critical Point32.97 K
Heat of Fusion0.05868 kJ/mol
Heat of Vaporization0.44936 kJ/mol


Energies
First Ionization Energy1312 kJ/mole
Second Ionization EnergyNil
Third Ionization EnergyNil
Electronegativity2.20
Electron Affinity72.7711 kJ/mole
Specific Heat14.304 J/gK
Heat Atomization218 kJ/mole atoms


Oxidation and Electrons
Shells1
Electron Configuration1s1
Minimum Oxidation Number-1
Maximum Oxidation Number1
Minimum Common Oxidation Number-1
Maximum Common Oxidation Number1


Appearance and Characteristics
Crystal Structurehexagonal
Characteristicsdiatomic, dens
Colorcolorless
Usesrocket fuel
Hardnessmohs
ToxicityNone


Reactions
Reaction with Airvigorous, => H2O
Reaction with 6M HClNone
Reaction with 15M HNO3None
Reaction with 6M NaOHNone


Other Forms
Number of Isotopes3
HydrideH2
OxideH2O
ChlorideHCL


Radius
Atomic Radius37.1 pm
Ionic Radius (1+ ion)Nil
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)Nil


Conductivity
Thermal Conductivity0.18 J/m-sec-deg
Electrical Conductivity1/mohm-cm
Polarizability 0.7 A3


Abundance
SourceWater, methane
Relation Abundance Solar System10.446 log
Abundance Earth's Crust3.1 log


s1
H
Hydrogen
s2
He
Helium