Some metals rust while others stay shiny for years. The reactivity series ranks metals by how eagerly each one reacts with its surroundings — a metal higher on the ranking corrodes sooner. You soak small squares of copper, aluminum, iron, and zinc in tap water, salt water, and lime juice, then check each piece after two days. Only one metal stays completely clean.

Some metals rust quickly while others stay shiny for years, because each metal's surface resists chemical breakdown differently. To test those differences, you cut small squares of copper, aluminum, iron, and zinc and place each in a beaker of tap water, salt water, or lime juice. After two days, you check each piece for visible breakdown. Only one metal stays completely clean across all three liquids.

Some metals rust while others stay shiny for years. When a substance combines with oxygen, that chemical reaction is called oxidation — and metals vary widely in how fast it happens. You immerse small squares of copper, aluminum, iron, and zinc in tap water, salt water, and lime juice, then check each surface after two days. Some pieces corrode; others do not.