eV?

[v1]

can somebody explain what eV is?
i don't really understand why it is the unit of maximum kinetic energy of electron

[jenslekman]

1eV = 1.6 x 10^-19 J

so it is basically another way of expressing energy ... hence kinetic energy of an electron...

the reason why we use eV is for the stopping voltage experiment (JJ thomson experiment i believe). in this experiment a voltage is applied to oppose the photoelectric current, and the voltage when the net current reaches zero is the stopping voltage (in eV). Since current is just a measure of the kinetic energy of an electron, the stopping voltage is the maximum kinetic energy of the electron.

[IamBread]

As stated above, 1eV = 1.6 x 10^-19 J

eV stands for electronvolt, it's just another unit of energy, but it is related to an electron. You could use joules, it doesn't matter.