Respuesta :
it states that the atom is neutral, meaning the number of electrons and protons are the same. so if there are 13 electrons, there are 13 protons. And the mass number is neutrons plus protons. So 13+15 is 28
Answer:
28
Explanation:
The atom is neutral, which means the quantity of electrons and protons square measure an equivalent. thus if there square measure 13 electrons, there square measure 13 protons. and therefore the nucleon number is neutrons and protons. thus 13+15 is 28
