Which subatomic particle is found outside the nucleus?

The subatomic particle that is found outside the nucleus is the electron. Electrons are negatively charged particles that exist in regions around the nucleus of an atom called electron shells or energy levels. They play a crucial role in chemical bonding and electrical conductivity.

Protons, which are positively charged, and neutrons, which have no charge, are both located within the nucleus of the atom. The nucleus serves as the central core of the atom, containing most of its mass due to the presence of protons and neutrons. The term "nucleus" itself refers specifically to this dense core and does not represent a subatomic particle in the same way that electrons, protons, and neutrons do. Thus, the nature and location of electrons distinctly categorize them as the particles that exist outside the nucleus.