A battery has two electrodes labeled anode
and cathode. Electrons flow from the (anode,
cathode) to the (anode, cathode) through the
external circuit and (an oxidation, a reduc-
tion) reaction occurs at the cathode.
1. anode; cathode; reduction
2. cathode; anode; oxidation
3. anode; cathode; oxidation
4. cathode; anode; reduction
Electrons flow from the negative electrode to the positive electrode. By definition, oxidation is the loss of electrons and reduction is the gain of electrons. Also, by definition, the anode is where oxidation occurs.
The correct answer is option 3: anode; cathode; oxidation.
To understand why, let’s break down the question:
1. Electrons flow from the (anode, cathode) to the (anode, cathode) through the external circuit.
Electrons flow from the anode to the cathode through the external circuit. This is a basic principle of how a battery works. The anode is the electrode where oxidation happens and electrons are generated. The cathode is the electrode where reduction occurs and electrons are received.
2. (An oxidation, A reduction) reaction occurs at the cathode.
A reduction reaction occurs at the cathode. In a reduction reaction, there is a gain of electrons. So, at the cathode, electrons are received, indicating a reduction reaction.
Based on these descriptions, we can conclude that the correct answer is option 3: anode; cathode; oxidation.