Read the Credit Card (Super Science Experiments)

You will need:

1. Sandpaper
2. Spoon
3. Rust powder (anything)
4. Old plastic card (which has a magnetic strip at the back)

Learn all about magnetic fingerprinting with
this experiment.

INSTRUCTIONS

1. Ask an adult to help you sand some rust off the rusty by object using sandpaper. Be careful not to hurt yourself.
2. Collect ¼ th teaspoon of rust powder by sanding the rusted object.
3. Wipe the magnetic strip on your old plastic card clean so that there may not be any dust or grease on it.
4. Very gently, take the rust powder and tap it onto the magnetic strip.
5. Gently, tap off the excess rust powder from the strip, and
   look at reflection created on
   the strip by reflecting a light
   source off it.

RESULT

The light reflecting off the magnetic strip will reveal that the rust is sticking to the strip in lines. This happens because the rust is attracted to the magnetized parts of the strip which store information. When the card is swiped through a reader, the magnetized parts are interpreted by the card reader into information. The rust will be attracted to only the magnetized parts of the strip, which has encoded data stored in different arrangements in different strips.