* Protons define the element: The number of protons in an atom's nucleus determines its atomic number, which is the fundamental identifier of an element. Every element has a unique atomic number. For example, all carbon atoms have 6 protons, all oxygen atoms have 8 protons, and so on.
* Changing the number of protons changes the element: If you add or remove protons from an atom's nucleus, you essentially change what element it is. For instance, if you add a proton to a carbon atom (6 protons), you turn it into a nitrogen atom (7 protons).
Other particles and their roles:
* Neutrons: Changing the number of neutrons in an atom's nucleus creates isotopes of the same element. Isotopes have the same number of protons but different numbers of neutrons. For example, carbon-12 and carbon-14 are both isotopes of carbon, but carbon-14 has 2 more neutrons than carbon-12.
* Electrons: Electrons are involved in chemical bonding and reactions, but changing their number doesn't change the atom's identity (its element). Adding or removing electrons creates ions, which are charged atoms.
In summary: Only changing the number of protons in an atom's nucleus will change the element and thus the name of the atom.
