Allen read that the gas company was burying sheets of magnesium next to pipelines to prevent rusting. He decided to investigate the effectiveness of various metals in preventing rusting. He placed the following
into three separate test tubes of water: A) Iron nail B) Iron nail wrapped with aluminum strip C) Iron nail
wrapped with magnesium strip. He used the same amount of water, equal amounts of the metals and the
same size iron nails. At the end of five days he recorded the amount of rusting on the nails and the color of
the water.