The proton and the neutron have mass each of one Atomic Mass unit. Actually they are not quite the same, but they are very close.
Atomic Mass units
No such particle exists. All particles with charge also have mass -- no exceptions. Every particle with zero mass also has zero charge -- no exceptions.
Technically all subatomic particles have mass. However, the electron is so small that it was once considered to have no mass. Wrong, both photons and gravitons are subatomic particles with no mass.
The three main subatomic particles are the proton, neutron, and electron. Of these three, the electron has the least amount of mass at about 0.0005 amu or atomic mass units.
Yes, a neutron has mass. The mass of a neutron is slightly greater than the mass of a proton, which is another subatomic particle found in the nucleus of an atom. Neutrons and protons are both much more massive than electrons, which are the smallest subatomic particles.
The electron is the subatomic particle with the least mass. It has a mass of about 1/1836 of a proton or neutron.
A neutron is the subatomic particle with a charge of 0 and a mass of 1 atomic mass unit.
The tau neutrino has mass and is denoted with the symbol μ.
An "element" is not a subatomic particle. Your question makes no sense and is therefore unanswerable.Another answer:Since an element is not a subatomic particle, the only answer can be a proton.
The neutron is a subatomic particle that has mass nearly equal to that of a proton but carries no electrical charge.
Matter
Protons and neutrons are roughly 1800 times heavier then electrons.
Protons and neutrons have the mass of 1 amu.
The electron has the smallest mass between subatomic particles: 9,10938291(40).10-31 kg.
neutron
the neutron
If you mean subatomic particle as in protons neutrons and electrons, electrons have the lowest mass. If you are talking even smaller, leptons have extremely tiny rest masses.