Which is the lightest particle of an atom?

Answer 1

Of the particles usually given as components of the atom... the electron, the neutron, and the proton... the electron is by far the lightest. If you want a simple answer, stop there; the rest of this gets nitpicky.

Under the standard model, the neutrons and protons are themselves composed of smaller particles called quarks (all of which are still more massive than electrons). However, since quarks have a color charge, they interact with each other through the color force, which is mediated by gauge particles called gluons.

There's also an electrical force between the charged particles, and the gauge particle for the electromagnetic force is the photon.

Both gluons and photons are massless, so they're tied for the title of "lightest particle".

(It's currently believed that if they exist gravitons must also be massless, making it a three-way tie. The fourth fundamental force... the weak nuclear force... is mediated by the very massive W and Z bosons, which aren't in the running.)

Answer 2

photon is one, it has zero mass. (0 eV) there are other zero mass bosons too.

neutrinos have small nonzero masses. (~1 eV)

electrons have significant mass. (0.511 MeV)

protons have larger mass. (938.2 MeV)

neutrons have slightly larger mass. (939.5 MeV)

Answer 3

The lightest subatomic particle is the electron. It has a mass that is vastly smaller than that of protons and neutrons.

Answer 4

Photons and neutrinos have a rest mass of zero.

Answer 5

The lightest particle of an atom is the electron. It has a much smaller mass compared to the protons and neutrons found in the nucleus of an atom.

Answer 6

an electron.

Answer 7

the electrons

Answer 8

The electron.

Answer 9

This particle is the electron.