Exam Question

### Part (a): The Term 'Corrosion' and its Natural Occurrence
**(i) Definition of Corrosion**
Corrosion is a natural, electrochemical process involving the gradual destruction of metals or alloys due to their chemical or electrochemical reaction with the surrounding environment. It is the tendency of a refined metal to revert to its more chemically stable and lower-energy state, typically as an oxide, sulfide, or carbonate, which is how most metals are found in their natural ore form.
From a scientific perspective, corrosion is defined as the simultaneous transfer of mass and charge across a metal/solution interface. For this process to occur, four essential components of an electrochemical cell must be present: