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 — and the liquid they sit in matters too. In this project, small squares of copper, aluminum, iron, and zinc are each placed in tap water, salt water, or lime juice for two days. After two days, you check each piece for surface damage. Not all metals react the same way: their surfaces resist chemical breakdown differently depending on both the metal and the liquid. Only one metal comes out 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.