In chemistry, we study about particles and the most common particles are electrons, neutrons and protons, the main difference among these particles are:
Proton - in the nucleus and has a positive charge
Neutron - in the nucleus and has no charge or neutral charge
Electron - outside of the nucleus, in the electrosphere, negative charge
Therefore the best match for this question is:
1. Electron
2. Proton
3. Neutron
4. Nucleus
