General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Hydrogen Symbol H
atomic number 1 Atomic weight 1.0079
Density @ 293 K 0.0000899 g/cm3 Atomic volume 14.4 cm3/mol
Group Non-Metal discovered 1766


state (s, l, g) g
melting point 14.06 K boiling point 20.4 K
Heat of fusion 0.05868 kJ/mol Heat of vaporization 0.44936 kJ/mol
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1st ionization energy 1312 kJ/mole electronegativity 2.2
2nd ionization energy kJ/mole electron affinity 72.7711 kJ/mole
3rd ionization energy kJ/mole Specific heat 14.304 J/gK
heat atomization 218 kJ/mole atoms

Oxidation & Electrons

Shells 1 electron configuration 1s1
minimum oxidation number -1 maximum oxidation number 1
min. common oxidation no. -1 max. common oxidation no. 1
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Appearance & Characteristics

structure hcp: hexagonal close pkd color colorless
uses rocket fuel toxicity
hardness mohs characteristics diatomic,dens


reaction with air vigorous, = H2O reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3 none
reaction with 6M NaOH none
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Other Forms

number of isotopes 3 hydride(s) H2
oxide(s) H2O chloride(s) HCl


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 37.1 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) pm
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thermal conductivity 0.18 J/m-sec-deg electrical conductivity 1/mohm-cm
polarizability 0.7 A^3


source Water, methane rel. abund. solar system 10.446 log
abundance earth's crust 3.1 log cost, pure 12 $/100g
cost, bulk $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.