Hydrogen General Information

• Class: Non-Metals
• Period: 1
• IUPAC group: 1
• Traditional: Ia

• Discovered in: 1766 by Cavendish
• Origin of name: Greek: hydro (water) + genes (forming) = (water forming)
• Historical or alternate name:

Water, organic matter such as plants, petroleum, coal, etc.

Colorless, odorless gas, insoluble in water, burns & forms explosive mixtures in air..

• Atmosphere: 0.53 ppm
• Primitive mantle: ~0.0 ppm
• Sea water: (H2O) ppm
• Metallic meteorite: 20200.0 ppm
• Continental crust: 1400.0 ppm
• Solar photosphere: 12.0 log of abundance
• Oceanic crust: ~0.0 ppm
• Solar system: 2.720E+10 relative to Si=1.0e6

   Hazards

Flammable gas. Explosive. No toxicity except for possible asphyxiation. Reacts violently with oxidants.

   Human daily limits

• Lower: Required
• Upper:

Hydrogen Physical Properties

 Transitional Data

• State: Gas
• Density: 0.0899 g/L

 Molar enthalpy

• Atomization: 216.003 kJ mol-1
• Fusion: 0.12 kJ mol-1
• Vaporization: 0.46 kJ mol-1

 Transition points

• Melting point: 14.01 K
• Boiling point: 20.28 K
• Critical temperature: 33.2 K

 Molar properties

• Atomic weight: 1.00794 g/mole
• Molar volume: 22.956 cm3 mol-1

 Crystal structure sequence

hexagonal-close-packed

 Thermodynamics

• State: gas (H2)
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 130.684
  • Heat Capacity 28.824

• State: gas (atoms)
  • Enthalpy 217.965
  • Gibbs function 203.247
  • Entropy 114.713
  • Heat Capacity 20.784

 Miscellaneous physical

• Electrical resistivity: µ-ohms/cm
• Debye temperature: K
• Thermal conductivity: 0.183 W / m / K
• Coefficient of linear expansion: Coef. per K
• Mass magnetic susceptibility: -2.50e-8
• X-ray diffraction mass absorption coefficients:
• CuK: 0.435 (µ/p)/cm2 g-1
• MoK: 0.380 (µ/p)/cm2 g-1

Hydrogen Chemical Properties

 Chemical basics:

• Oxidation states: -1 +1
• Molecular wt: 1.00794 g/mole

 Radii

• Covalent: 30 pm
• Atomic: 37.0 pm
• Van der Waals: 120 pm

 Ions:

 Covalent bonds

 Effective nuclear charge

• Slater: 1.00
• Clementi: 1.00
• Froese-Fischer: 1.00

 Electronegativity

• Pauling: 2.1
• Allred-Rochow:

 Standard reactions

Hydrogen Nuclear Properties

• Known 3
• Listed 3

• Known 1 - 3
• Listed 1 - 3

• % Occ.:Natural 99.985%
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 1/2
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural 0.015%
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 1/0
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 1/2
• Radioisotopes:
  • Half-life: 12.43 years
  • Decay mode: Beta-
  • Source: Cosmic irradiation.
• Notes date med

• Isotope Cross-section 0.332±0.002 barns

• Absolute sensitivity: 1.00 1H=1.0
• Relative sensitivity: 1.00 1H=1.0
• Receptivity: 5680 13C=1.0
• Magnetogyric ratio: 26.7510e7 rad / T / s
• Quadropole moment: m2
• Frequency: 100.000 MHz
• Reference: Si(CH3)4

• Absolute sensitivity: 5680 1H=1.0
• Relative sensitivity: 1.00 1H=1.0
• Receptivity: 26.7510e7 13C=1.0
• Magnetogyric ratio: rad / T / s
• Quadropole moment: 100.000 m2
• Frequency: 2 MHz
• Reference: Si(CH3)4

Hydrogen Energy Properties

Electrons

• Ground state electron configuration: 1s1
• Electron affinity: 72.8 kJ mol-1
• Filling orbitals:

 Ionization energies

 Atomic energy levels