Here are the matched descriptions with the correct subatomic particle:
- Neutral particle found in the nucleus. - Neutron
- Positively charged particle in the nucleus of an atom. - Proton
- The subatomic particle with the smallest mass. - Electron
- Negatively charged particle found outside the nucleus. - Electron
(Note: The electron is mentioned twice, as it fits both the smallest mass and the negatively charged particle descriptions.)