Invisible Ink: A Fun Science Experiment

Stuff You’ll Need:

Experiment:

1. Have an adult cut the lemon in half and squeeze some juice into a bowl. This is your ink.
2. Dip the end of the cotton swab, paint brush or your finger into the “ink” and use it write a secret message or draw a picture onto a piece of paper.
3. Let the juice dry. The paper will look blank.
4. To read your secret message or show it to someone else, heat the paper by running an iron set on high heat over it for about 45 seconds.

What Happened?
Lemon juice is an organic substance that oxidizes and turns brown when heated.