Is this redox reaction balanced?

Which statement correctly describes a redox reaction?

• The oxidation half-reaction and the reduction-half reaction occur simultaneously. The oxidation half-reaction occurs before the reduction half reaction. The oxidation half- reaction occurs after the reduction half-reaction. The oxidation half-reaction occurs spontaneously but the reduction half-reaction does not.

• Answer:

  The Oxidation half-reaction and the Reduction-half reaction occur simultaneously. Think of it this way when you are doing and Oxidation Reduction lab you have two solutions that are connected with a salt bridge that it for the flow of the ions and you have two pieces of metal in each solution connected by a wire to each other. One of them will be oxidized and the other will be reduced but they occur at the same time. If one happens and the other does not, then there is no reaction because there is no anode to cathode or any electron flow because they complement each other.