Answer:
Neutrons and protons
Explanation:
There are three fundamental subatomic particles, these are;neutrons protons and electrons.
Ernest Rutherford successfully showed that every atom does possess a central core that contain positively charged particles (protons) called the nucleus. Chadwick later discovered the existence of neutrons.
Both protons and neutrons are found in the nucleus. Z represents the nucleus of the boron atom and houses the neutrons and protons of the boron atom.
