Which subatomic particle is the smallest in terms of mass?

• A. Neutron
• B. Alpha particle
• C. Electron
• D. Proton

Answer: (C)

Verified step by step guidance

1. Recall the three main subatomic particles: protons, neutrons, and electrons, and understand that an alpha particle is a cluster of two protons and two neutrons.
2. Compare the masses of the individual subatomic particles: protons and neutrons have masses close to 1 atomic mass unit (amu), while electrons have a much smaller mass.
3. Recognize that an alpha particle, being composed of multiple protons and neutrons, has a mass roughly four times that of a single proton or neutron.
4. Understand that the electron's mass is approximately 1/1836 that of a proton or neutron, making it significantly lighter than the other particles listed.
5. Conclude that among the options given, the electron is the smallest subatomic particle in terms of mass.