When considering the precise mass of subatomic particles, which particle has the greatest mass?

• A. Electron
• B. Positron
• C. Proton
• D. Neutron

Answer: (D)

Verified step by step guidance

1. Recall the three main subatomic particles: electron, proton, and neutron. The positron is the antimatter counterpart of the electron and has the same mass as the electron.
2. Understand that the electron and positron have very small masses compared to protons and neutrons. Both electron and positron masses are approximately 9.11 \times 10^{-31} kg.
3. Compare the masses of the proton and neutron. Both are much heavier than electrons and positrons, with masses on the order of 1.67 \times 10^{-27} kg.
4. Note that the neutron has a slightly greater mass than the proton. The neutron's mass is about 1.675 \times 10^{-27} kg, while the proton's mass is about 1.673 \times 10^{-27} kg.
5. Conclude that among the given particles, the neutron has the greatest mass, followed closely by the proton, and then the electron and positron with much smaller masses.