A photon is a particle that
A) has a velocity in a vacuum that varies with the photon frequency.
B) cannot travel in a vacuum.
C) has zero electric field associated with it.
D) has zero electric charge.

Question

Quizplus · Accepted Answer

Photons, which are the quantum particles of light, indeed have zero electric charge. This is a fundamental property of photons that distinguishes them from charged particles like electrons or protons. Choices A, B, and C are incorrect because the velocity of a photon in a vacuum is constant (the speed of light, approximately 3 x 10^8 meters per second) and does not vary with frequency, photons can and do travel in a vacuum (in fact, space is a vacuum and light travels through it), and photons are associated with both electric and magnetic fields, as they are electromagnetic waves in quantum form.

A Photon Is a Particle That