Periodic Table Poster   My periodic table poster is now available!Periodic Table PosterPeriodic Table PosterPeriodic Table Poster
3D3DOil tank sacrificial anodes.
These little zinc balls are put into oil tanks to prevent rust: The idea is that the zinc oxidizes more easily than iron, so it gets consumed before the iron does. As long as you keep some zinc around, the iron will generally speaking not rust. The same idea is used to protect boat hulls, railroad tracks, and other steel structures. The zinc is simply buried in the ground near the iron and connected with a wire.

I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.
Periodic Table Poster

Source: eBay seller kaltofen
Contributor: Theodore Gray
Acquired: 14 February, 2003
Text Updated: 4 May, 2007
Price: $11/3
Size: 1"
Purity: >99%