Write spooky messages for your friends with invisible ink! Just paint lemon juice on printer paper with a Q-Tip, let it dry and reveal the message using heat from a candle flame via oxidation! Adult supervision is required when using candles. You can also reveal your message using a very hot light bulb, but we had better luck with a flame.
You can see how it looks in the segment below. We also dusted for fingerprints on glasses with chalk and cocoa powder to get ready for the Science Museum of Minnesota’s upcoming Sherlock exhibit.