Answer:
Electron
Step-by-step explanation:
The atom of an element is its smallest indivisible particle. The structure of an atom is composed of smaller particles called SUBATOMIC PARTICLES. These subatomic particles are proton, neutron (located in the nucleus) and electron (located outside of the nucleus).
The proton is the positively charged (+) particle of an atom while the ELECTRON is the negatively charged (-) particle of an atom. Note that, an atom will be positive or negative depending on the amount of these particles.