The lightest of the subatomic particles is the a. proton b. nucleus c. atom d.electron e. neutron
The correct answer and explanation is:
Correct Answer: D. Electron
The electron is the lightest of all subatomic particles. It has a mass of approximately 9.11 × 10⁻³¹ kilograms, which is significantly smaller than the masses of protons and neutrons. To put it into perspective, the mass of an electron is about 1/1836 the mass of a proton or neutron.
A proton has a mass of about 1.67 × 10⁻²⁷ kilograms, and a neutron is slightly heavier, with a mass of approximately 1.675 × 10⁻²⁷ kilograms. Both protons and neutrons are located in the nucleus of the atom, and they account for nearly all of an atom’s mass. The nucleus is not a subatomic particle itself but rather a structure composed of protons and neutrons, so it cannot be considered lighter than the electron. Similarly, an atom includes protons, neutrons, and electrons, making it far heavier than any individual subatomic particle.
Electrons carry a negative electrical charge and orbit the nucleus at high speeds in regions called electron clouds or orbitals. Because they are so light, their contribution to the total mass of an atom is almost negligible. However, they play a critical role in chemical bonding and electrical conductivity.
Despite their small mass, electrons are extremely important in determining the chemical properties of elements. They are involved in interactions between atoms, including forming bonds, releasing or absorbing energy, and facilitating reactions.
To summarize, among all the listed options, the electron is by far the lightest subatomic particle and is fundamental to the structure and function of atoms in chemistry and physics.