Which subatomic particle will you add or remove from an atom to create a new element? a- protons b- neutrons c- electrons

I believe it is b neutrons

As newton's first law states a object in motion stays in motion

Is there any opitions? if you have the periodic table, the noble gases are 8a family, the halogen are the 7a family, and the nonmetal are  carbon, nitrogen, phosphorus, oxygen, sulfur, selenium, fluorine, chlorine, bromine, iodine and astatine.