Science Birthday Party
Lemon Juice Invisible Ink
Lemon juice is virtually invisible but oxidizes and turns brown when warmed or heated. This reaction to heat is the perfect way to create secret messages for science parties or secret laboratory formulas. The lemon juice is invisible when dry, but once you add heat, the message is revealed!
- lemon juice
- small craft paintbrush
- iron or light bulb
- Have each child write a hidden message on a piece of paper with the lemon juice and paintbrush.
- Once the paper is dry, carefully apply heat with an iron. (A lit light bulb works as well, but takes longer.)
- Watch and see the message appear!