Which of the following accurately describes the mass of an electron?

The mass of an electron is indeed negligible compared to a proton. The mass of an electron is approximately 9.11 x 10^-31 kilograms, while the mass of a proton is about 1.67 x 10^-27 kilograms. This significant difference demonstrates that electrons are much lighter than protons and also neutrons, which have similar masses to protons. In the context of atomic structure, while electrons contribute to the overall charge of an atom and play critical roles in chemical bonding, their mass is so small that it is often considered negligible when calculating the overall mass of an atom, which is dominated by protons and neutrons in the nucleus.