The correct answer is A) the number of electrons that fill the outer shell.
Brady
Atoms are fundamental constituents of all matter. The following statement is correct. The nucleus always has a positive charge. This is because the nucleus contains sub-atomic particles called protons. Each proton carries a single positive charge. The nucleus is also home to sub-atomic particles called neutrons that do not possess a charge.
Answer:
the mass number decreases by 4 and the atomic number decreases by 2
