Question

when a battery is supplying power, which battery terminal is the cathode?
a) negative
b) positive

Explanation:

In a battery supplying power (discharging), oxidation occurs at the anode and reduction occurs at the cathode. Electrons flow from the anode to the cathode. The positive terminal of the battery is where reduction takes place (cathode in a discharging battery). In a galvanic cell (which a battery is when discharging), the cathode is the positive terminal.

Answer:

B. Positive