Electronvolt

An electronvolt (eV) is a unit of energy commonly used in atomic, nuclear, and particle physics to measure the energy carried by individual particles and electromagnetic radiation. It’s a convenient unit because the energies involved in these fields are much smaller than what we encounter in everyday life.

• Electronvolts can be used to measure the energy of elementary particles, including photons, which are the smallest units of electromagnetic radiation (quanta of the electromagnetic field).
• One electronvolt is equal to the energy gained by a single electron when it is accelerated across a potential difference of 1 volt.
• Photons (quanta of light) travelling through this same potential difference would also gain 1 eV of energy.
• The electronvolt is not part of the SI unit system. The SI unit for energy is the joule (J). However, joules are too large for many particle-level interactions.
• 1 electronvolt (eV) is equivalent to approximately 1.602 x 10^-19 joules (J).
• The electronvolt is often used in conjunction with metric prefixes to represent energy values at different magnitudes.
• kiloelectronvolt (keV): 1 keV = 1,000 eV (used for energies of X-rays)
• megaelectronvolt (MeV): 1 MeV = 1,000,000 eV (used for energies of gamma rays and nuclear reactions)
• gigaelectronvolt (GeV): 1 GeV = 1,000,000,000 eV (used for energies of particles in particle accelerators)
• teraelectronvolt (TeV): 1 TeV = 1,000,000,000,000 eV (used for energies of very high-energy particles in cosmic rays)
References
• An electronvolt (eV) is a unit of energy commonly used in atomic, nuclear, and particle physics to measure the energy carried by individual particles and electromagnetic radiation. It’s a convenient unit because the energies involved in these fields are much smaller than what we encounter in everyday life.
• Electronvolts can be used to measure the energy of elementary particles, including photons, which are the smallest units of electromagnetic radiation (quanta of the electromagnetic field).
• One electronvolt is equal to the energy gained by a single electron when it is accelerated across a potential difference of 1 volt.
• Photons (quanta of light) travelling through this same potential difference would also gain 1 eV of energy.
• The electronvolt is not part of the SI unit system. The SI unit for energy is the joule (J). However, joules are too large for many particle-level interactions.
• 1 electronvolt (eV) is equivalent to approximately 1.602 x 10^-19 joules (J).