Hydrogen
Symbol: H
Atomic mass: 1.0079 amu
Isotopes:
| Isotope | %Abundance | At. Mass | T1/2 | Modes of decay | Decay Energy (MeV) | Particles Energy(MeV) |
| 1H | 99.985 | 1.007825 | ||||
| 2H | 0.015 | 2.0140 | ||||
| 3H | 3.01605 | 12.26y | b- | 0.01861 | 0.01861 |
Historical Perspective:
Name: from Greek words hydro – water and genes – forming.
Discover: Cavendish in 1766
Chemistry:
Abundance: Most abundance element in the universe. Approximate 90% of all the mass of the atoms and 75% of all the mass of matter. On Earth, there is very little free hydrogen (less than 1ppm in the atmosphere). It occurs mostly in combination with oxygen in water and is also present in organic matter.
Uses:.
 | Fixation of nitrogen |
| Hydrogenation of fats and oils |
| Production of methanol |
| Hydrodealkylation |
| Hydrocracking |
| Hydrodesulfurization |
| Rocket fuel |
| Welding |
| Production of hydrochloric acid |
| Reduction of metallic ores. |
| Cryogenics |
| Study of superconductivity. |
| Fuel cell |
Preparations:
| Steam on heated carbon |
| Decomposition of certain hydrocarbons with heat |
| Electrolysis of water |
| Displacement from acids by certain metals |
| Sodium (or Potassium) hydroxide with Aluminum. |