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The electron-volt (unit of energy)
In particle physics, a unit of energy is commonly used: the electron-volt (eV).
1 eV = 1.6 10-19 Joules
- A 60 Watts electric lamp uses 60 Joules per second to give some light to you.
- 1 GeV = 1 billion of electron-volts
- A flying mosquito (0.01 g) is composed of about 3 1019
atoms and, to climb one meter, it needs about 0.0001 Joule,
that is about 30 millionth of electron-volt per atoms of mosquito.
Moreover, particles masses are expressed in a more convenient way thanks to the electron-volt.
The famous equation E = mc2 gives the following relationship:
1 eV/c2 = 1.8 10-36 kg
An electron, for instance, has a mass of 511 keV, that is about 10-30 kg.
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Last update: 26/06/1999 : http://wwwlapp.in2p3.fr/neutrinos/agev.html
Didier Verkindt