one electron would be added the atomic number would change the total mass of the atom would decrease the electrical charge would become neutral
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: What would be the result of adding one proton to an atom?
Possibilities:
- one electron would be added
- the atomic number would change
- the total mass of the atom would decrease
- the electrical charge would become neutral

the atomic number would change