H |
| Hydrogen |
| Atomic no.: |
1 |
| Atom. weight: |
1.00794 |
| Density: |
0.08988 |
| Class: |
Gas |
| Melting point: |
-259.14°C |
| Boiling point: |
-252.76°C |
| Colour: |
colourless |
| |
|
| Discoverer: |
Henry Cavendish |
| Place: |
London, England |
| Year: |
1766 |
|
Hydrogen. from the greek words "hydro" and "genes" meaning "Water-generator" Tritium is an isotope of hydrogen which has one proton and two neutrons . It emits beta particles only and has a half-life of 12.3 years. The maximum beta energy is 18 keV, and the mean beta energy is 6 keV. A beta particle with energy of less than 70 keV will not penetrate the dead outer layer of the skin. Therefore, tritium is not an external radiation hazard , but when taken into the body it becomes an internal hazard .
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