Question:What are particles?
The word particle literally just means a very small part (part - icle).
In Science we extend this a little to mean the very smallest parts.
The smallest parts of any material are the atoms or molecules that make up the material so we say the particles are the atoms or the molecules.
The smallest parts in an atom are the electrons, protons and neutrons.
Since the nucleus is made up of smaller parts we tend not to call the nucleus a particle.
We can further extend our definition by adding adjectives such as subatomic.
Subatomic particles are the particles that make up an atom, the electron, neutron and proton.