Which subatomic particle has negligible mass?

Correct answer: (c) Electron

Explanation

The electron has a mass of about 9.1 × 10⁻³¹ kg, roughly 1/1836 of a proton's mass, so its mass is treated as negligible.

Protons and neutrons each weigh about 1.67 × 10⁻²⁷ kg, which is why almost all of an atom's mass lies in its nucleus.