Final answer:
The cathode is the negatively charged electrode in an electrochemical cell where reduction occurs. Electrons are gained at the cathode, and in processes like electrolysis and electroplating, the object or substance at the cathode undergoes reduction. So, the correct option is 2) the negatively charged electrode of a battery or electrochemical apparatus
Step-by-step explanation:
The statement that best describes a cathode is the second option: it is the negatively charged electrode of a battery or electrochemical apparatus.
In electrochemical cells, oxidation occurs at the anode, while reduction occurs at the cathode.
Electrons flow from the anode to the cathode, and thus the cathode is where electrons are gained, which leads to reduction reactions.
For instance, in a lithium-ion battery, the lithium ions are transferred between the anode and cathode, with electrons flowing through the external circuit from the anode to the cathode.
During electrolysis, the cathode becomes negatively charged because of the flow of electrons towards this electrode to undergo the reduction process.
As electroplating involves coating an object with a layer of metal, the object is made the cathode as it gains electrons and hence is subjected to reduction.
In summary, the cathode is the electrode where reduction takes place and is negatively charged.
Therefore, the correct option is 2) the negatively charged electrode of a battery or electrochemical apparatus