Pick the answer that best answers the question. an oxygen atom has 8 protons and 8 neutrons. if an extra neutron is gained for a total of 9 neutrons, what can be said about our atom? (a) the atom's identity has changed and can no longer be called oxygen (b) the altered atom is an isotope of oxygen (c) the nucleus must gain an extra proton to balance the change (d) the atom must gain an extra electron in order to maintain its identity