Exam Question

### Part (a): Corrosion and its Occurrence in Nature (6 Marks)
**Definition of Corrosion:**
Corrosion is a natural electrochemical process that causes the degradation of a metal due to its reaction with the surrounding environment. It represents the tendency of refined metals to revert to their more thermodynamically stable, naturally occurring compound state, such as oxides, sulphides, or carbonates. This reversion from a high-energy pure metallic state to a lower-energy compound state releases the energy that was originally supplied during the smelting and refining process.
Scientifically, corrosion is defined as the simultaneous transfer of mass and charge across a metal/solution interface, forming an electrochemical cell.