Fundamental Particles

Matter is composed of combinations of subatomic or fundemental particles made up of quarks bound together by glouns.


Electrons typically have a negative charge (negaton) but may also have a positive charge (positron). The charge of an electron is \(e = -1.60219 \cdot 10^{-19} \; [C]\). The process of electron annihilation occurs when a positron collides with a negatron releasing two of more photons known as annihilation radiation.


Protons have a positive charge equal and opposite to an electron.


Neutrons are electrically neutral and have a mass similar to a proton. Neutrons are not stable on their own; only when bounded within a nucleus. A free neutron decays into a proton with the emission of a negative electron and an antineutrino ( \( \beta \) decay) in a process that takes about 12 minutes.


Photons are the particle associated with electromagnectic waves. Photons have no charge or mass and travel in vacuum at the speed of light ( \( c = 2.9979 \cdot 10^8 \; [m/s]\) )


Neutrinos are another particle with no charge or mass. Those common to nuclear engineering are electron neutrinos and electron antineutrinos.

Element Mass \( \; [kg] \) Charge \( \; [C] \)
Electron \(9.10954 \cdot 10^{-31}\) \(-1.60219 \cdot 10^{-19}\)
Proton \(1.67265 \cdot 10^{-27}\) \(1.60219 \cdot 10^{-19}\)
Neutron \(1.67495 \cdot 10^{-27}\) \(-\)
Photon \(-\) \(-\)
Neutrinos \(-\) \(-\)

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