What is an electron volt?

An electron volt, or eV for short, is a measure of energy. It is quite a small amount of energy similar to the amount of energy possessed by a single photon of light. Other forms of radiation have much more energy. On this web-site energies are often quoted in scientific notation. For example 106 eV is equal to 1,000,000 eV. i.e. 1 with 6 zeroes after it. In another example 3x109 eV would be equal to 3 with 9 zeroes after it or 3,000,000,000 eV.

Here are some examples of radiation of different energies.

RadiationEnergy
Photon of light
Can be detected by your eye
1 eV
Ultra Violet ray from sun
Enough to burn your skin
10 eV
X-Ray
Can pass right through your body
1000 eV = 1 keV
Gamma ray
detected by the Whipple group's telescope
1012 eV = 1 TeV
Cosmic Ray
detected by the SPASE-2 experiment
1015 eV = 1 PeV
Cosmic Ray
detected by the planned Pierre Auger Observatory
1020 eV = 100 EeV
Highest energy Cosmic Ray ever recorded3x1020 eV
This is the amount of energy that you would feel if you dropped a bowling ball on your foot from a height of 1 metre!
We have some other shorthand notation described below.

EnergyShorthand
103 eV = 1,000 eVKev = Kilo electron volt
106 eV = 1,000,000 eVMeV = Mega electron volt
109 eV = 1,000,000,000 eVGeV =Giga electron volt
1012 eV = 1,000,000,000,000 eVTeV = Terra electron volt
1015 eV = 1,000,000,000,000,000 eVPeV = Peta electron volt
1018 eV = 1,000,000,000,000,000,000 eVEeV = Exa electron volt
1021 eV = 1,000,000,000,000,000,000,000 eVZeV = Zeta electron volt