An electrically neutral object is given a positive charge.
(a) In principle, does the object's mass increase, decrease, or stay the same as a result of being charged?
(b) Choose the best explanation from among the following:
I. To give the object a positive charge we must remove some of its electrons; this will reduce its mass.
II. Since electric charges have mass, giving the object a positive charge will increase its mass.
III. Charge is conserved, and therefore the mass of the object will remain the same.