Electron is defined as?

• A. A negatively charged particle with little mass that orbits the nucleus.
• B. A positively charged particle in the electron cloud.
• C. A heavy neutral particle in the nucleus.
• D. A particle responsible for strong nuclear force.

Answer: (A)

Electrons are light, negatively charged subatomic particles that form the surrounding electron cloud around the nucleus. Their small mass compared to protons and neutrons lets atoms balance electrical charge while placing most of the atom’s positive charge in the nucleus. In simple terms, electrons are the negative partners that occupy space around the nucleus and drive chemical behavior. They aren’t heavy or neutral, they aren’t inside the nucleus, and they don’t mediate the strong nuclear force. So the description of a negatively charged particle with little mass that orbits the nucleus fits best. (In modern quantum terms, electrons occupy orbitals—regions of probability around the nucleus—rather than fixed paths.)