Aqueous copper(II) sulfate is electrolysed with copper electrodes. Which statement correctly describes the changes during the electrolysis?
- ACopper atoms gain electrons at the cathode and copper(II) ions lose electrons at the anode.
- BElectrons move in the external circuit from the positive electrode to the negative electrode.
- CCopper(II) ions move through the electrolyte from the cathode to the anode.
- DCopper is formed at the cathode and oxygen is formed at the anode.