Valero Mechanical Aptitude Practice Test

The cathode is the electrode where reduction occurs. In electrochemical cells, electrons flow into the cathode from the external circuit and ions in solution gain those electrons, becoming reduced. That’s why cations—positive ions—migrate toward the cathode to be reduced.

Note that the cathode’s apparent polarity depends on the type of device: in a galvanic (voltaic) cell, the cathode is the positive terminal, while in an electrolytic cell it is the negative terminal. Anion and cation refer to ions, not electrodes, so they aren’t the cathode.