Chapter 27, Problem 14Q

To determine

The difference between a photon and an electron.

Explanation of Solution

The specific difference of a photon and an electron are given below

1. Photon is a packet of energy while electron is a mass with charge.

2. Both are elementary particles but the photon is boson, particle carrying the force which moves the things. While electron is fermion, particle which constitute the things.

Spin: Photon has unit spin while electron has half spin. To reach initial point electron has to turn around twice while photon has to turn around once.

Mass: Electrons have less mass of 9 x 10^-31kg while photons have no mass. Rest mass of electron is 510.99 KeV while photons have no mass.

Charge: Electrons have an electric charge is negative (-1.6×10^-19 C). Photons does not have charge.

Antiparticle: Electrons have an antiparticle called positron but photons are antiparticles to themselves.

Speed: Electron speed may be zero, or anything less than the speed of light. A photon in a vacuum, it travels at exactly with the speed of light and a bit slower in denser medium.

Duality: Both of them having duality nature but photon displays more wave properties while electron displays more particle properties.