Respuesta :
Answer:
the atom number
Explanation:
atoms are determend by the numbers of protons in their core, as the number of protons determines what type of element the atom will be (noble gasses, Alkali Metals, Other Metals) and the atom number involves both protons and neutrons
Also spelling may be bad, as Grammarly dosen't work with brainly at all. and if its right brainlist plz (´~`ヾ)