From an Electron-Volt to Trillions of Electron-Volts

Energies are often expressed in units of "electron-volts". An electron-volt (eV) is the energy acquired by a electron (or any particle with the same charge) when it is accelerated by a potential difference of 1 volt.

• Typical energies involved in atomic processes (processes such as chemical reactions or the emission of light) are of order a few eV. That is why batteries typically produce about 1 volt, and have to be connected in series to get much larger potentials.
  

• Energies in nuclear processes (like nuclear fission or radioactive decay) are typically of order one million electron-volts (1 MeV).

• The highest energy accelerator now operating (at Fermilab) accelerates protons to 1 million million electron volts (1 trillion electron volts, 1 TeV =10¹² eV).

• The Large Hadron Collider (LHC) at CERN will accelerate each of two counter-rotating beams of protons to 7 TeV per proton.