Which of the following subatomic particles has the least mass?

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

Answer: (C)

Verified step by step guidance

1. Identify the subatomic particles mentioned: alpha particle, proton, electron, and neutron.
2. Recall that an alpha particle consists of 2 protons and 2 neutrons, so its mass is roughly 4 times that of a proton or neutron.
3. Understand that protons and neutrons have similar masses, both significantly greater than that of an electron.
4. Recognize that the electron is a fundamental particle with a mass approximately 1/1836 that of a proton or neutron.
5. Conclude that among the given options, the electron has the least mass.