Which subatomic particle has the smallest mass? a neutron proton an electron an alpha particle
The Correct Answer and Explanation is:
Correct Answer: c) an electron
Explanation:
The correct answer is an electron. When comparing the fundamental components of an atom and the composite alpha particle, the electron possesses a significantly smaller mass than all other options.
An atom is primarily composed of three fundamental subatomic particles: protons, neutrons, and electrons. Protons and neutrons are found clustered together in the atom’s central core, the nucleus. Due to their location and similar, substantial masses, they are collectively known as nucleons. A proton has a mass of approximately 1.672 x 10⁻²⁷ kilograms (kg), and a neutron is slightly heavier, with a mass of about 1.674 x 10⁻²⁷ kg. For simplicity, both are often assigned a relative mass of 1 atomic mass unit (amu).
In stark contrast, the electron is an extremely lightweight particle that orbits the nucleus. Its mass is only about 9.109 x 10⁻³¹ kg. This is roughly 1/1836th the mass of a proton. Because its mass is so insignificant compared to that of protons and neutrons, it is often considered negligible when calculating an atom’s total mass number.
The fourth option, an alpha particle, is not a fundamental subatomic particle. It is a composite particle, specifically the nucleus of a helium atom, consisting of two protons and two neutrons bound together. Consequently, its mass is the sum of its components, making it approximately four times more massive than a single proton or neutron and the most massive particle on the list.
Therefore, arranging the particles from most massive to least massive gives the following order: alpha particle > neutron > proton > electron. The electron is, by a very large margin, the particle with the smallest mass.
