What carries the current through the external circuit in an electrolysis setup?

• A. Electrons are transferred through the wires
• B. Ions move through the electrolyte to carry current
• C. Protons move through the wires
• D. Neutrons pass through materials

Answer: (A)

Electric current is the movement of charge, and in a metal wire the charge carriers are electrons. So, in the external circuit of an electrolysis setup, electrons flow through the wires to carry the current. Inside the electrolyte, ions move to carry current there, but that happens within the solution, not in the external circuit. Protons don’t move through wires in this context, and neutrons don’t carry charge. Therefore, electrons moving through the wires is what carries the current.