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What makes iron rust?

Four tubes with an iron nail: water and air, dry air, boiled water under oil, salt water.

Topic: Rocks and metalsGrade: 8Free

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What you do

  1. Put an iron nail in each tube.
  2. Press “+1 day” five times: a school week passes.
  3. Only tube 1 rusts. What does iron need to rust?
  4. Compare tubes 1 and 4: salt water makes rusting faster (cars near the sea!).

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