(a) Explain the differences between corrosion, wear and erosion-corrosion. (3 marks) (b) Identify the basic electrochemical reaction pair on which all electrochemistry is based, give examples. Which one gives the anode and which one gives the cathode side of the circuit? (4 marks) (c) Annealing is a commonly used thermal techniques in the processing of metals. Explain the steps of an annealing treatment. (5 marks) (d) Explain in detail while illustrating with examples 4 types of corrosion mechanisms.