In different experimental trials, an electron, a proton, or a doubly charged oxygen atom (O--) is fired within a vacuum tube. The particle's trajectory carries it through a point where the electric potential is 40.0 V and then through a point at a different potential. Rank each of the following cases according to the change in kinetic energy of the particle over this part of its flight, from the largest increase to the largest decrease in kinetic energy. (Use only ">" or "=" symbols. Do not include any parentheses around the letters or symbols.)
(a) An electron moves from 40.0 V to 60.0 V.
(b) An electron moves from 40.0 V to 20.0 V.
(c) A proton moves from 40.0 V to 20.0 V.
(d) A proton moves from 40.0 V to 10.0 V.
(e) An O-- ion moves from 40.0 V to 60.0 V.