What orders the list of metals in order of their electrical potential?

• A. The Nernst equation
• B. The galvanic series
• C. Pourbaix diagram
• D. The corrosion chart

Answer: (B)

The main idea here is that metals and alloys are ranked by their tendency to corrode in a given electrolyte, which is captured by the galvanic series. This list orders metals from most active (anodic) to most noble (cathodic) in a specific environment. When two metals are joined and exposed to an electrolyte, the metal lower in the series tends to corrode first and act as the anode, while the metal higher in the series behaves as the cathode and is protected. The exact order can shift with different electrolytes, temperatures, or surface conditions, but the standard galvanic series is the reference used to predict galvanic corrosion in aviation materials—informing choices about fasteners, alloys, and coatings. The other options don’t provide that direct ranking: the Nernst equation links electrode potential to ion activities but doesn’t rank metals, Pourbaix diagrams map stability of species against pH and potential, and a corrosion chart is a general guide rather than a ranking system.