Help needed stress can't seem to figure out! fill in the blank

one mole of gaseous chlorine and - yield two moles of aqueous potassium chloride and one mole of liquid bromine

In chemistry, the type of an atom (what element it is) is determined by: a) the number of protons it contains in its nucleus.b) the number of neutrons it contains in its nucleus.c) the number of protons it has in a cloud around the nucleus.d) the number of neutrons it has in a cloud around the nucleus.e) the number of electrons it exchanges with its neighbors.