Sacrificial protection is a method used to protect steel (mainly iron) structures, such as ship hulls, from corrosion. Blocks of a more reactive metal, such as magnesium, are attached to the steel. Which statement correctly explains how magnesium protects the iron?
Magnesium is more readily reduced than iron.
Magnesium gains electrons more easily than iron.
Magnesium is more readily oxidised than iron.
Magnesium is less readily oxidised than iron.