What are the components of an electrochemical cell?

An electrochemical cell is fundamentally composed of two different electrodes and an electrolyte. The electrodes are typically made from different materials, often metals, that facilitate either oxidation or reduction reactions. The two electrodes serve as the sites where these reactions occur: one electrode undergoes oxidation, releasing electrons, while the other undergoes reduction, accepting electrons.

The electrolyte, which is a substance containing free ions that carries electric current, is crucial because it allows ionic movement between the two electrodes, thereby enabling the electrochemical reactions to take place. This movement of ions is what balances the charge as electrons flow through the external circuit.

In contrast, the other options provided do not accurately represent the components necessary for an electrochemical cell. A semiconductor, on its own, does not fit into the basic structure of a cell, nor does having a single electrode or two electrolytes without the necessary corresponding components fulfill the requirements of an electrochemical system. Therefore, the combination of two different electrodes and an electrolyte is essential for the functioning of an electrochemical cell, making this the correct answer.