Here's why:

* Protons are positively charged particles found in the nucleus of an atom. The number of protons defines what element an atom is. For example, all carbon atoms have 6 protons, all oxygen atoms have 8 protons, and so on.

* Neutrons are neutral particles also found in the nucleus. While the number of neutrons can vary within an element (creating isotopes), the number of protons always stays the same.

* Electrons are negatively charged particles that orbit the nucleus. The number of electrons in a neutral atom is equal to the number of protons.

Let me know if you have any other questions!