🔍 Key Concepts

• Active vs. passive corrosion appearance on metals • Typical color and texture of corrosion products on copper alloys • Difference between stable protective films and signs of ongoing metal loss

💭 Think About

• For each choice, ask: does this describe a stable, protective surface layer or an indication that metal is still actively being eaten away? • Think about the typical colors and textures seen on old bronze or copper fittings that have stopped corroding quickly versus fittings that are still degrading. • Which option suggests a softer, possibly flaking or dusty product that would not protect the metal underneath?

✅ Before You Answer

• Identify which description matches a stable patina commonly seen on aged copper/bronze exposed to air and seawater. • Identify which description suggests loose, easily removed corrosion product rather than a tight, adherent film. • Eliminate any option that sounds like a normal, long-term weathered appearance rather than a symptom of current, aggressive corrosion.