Hot Science: Secret Message

What you need:

• - White paper
• - 1/4 cup lemon juice
• - Plastic cup
• - Cotton swab

Steps:

1. Put the lemon juice in the cup.
2. Dip the cotton swab into the lemon juice.
3. Use the swab to write your secret message on a sheet of paper.
4. Let the message dry and watch it disappear.
5. Pass off the secret message to your friend and tell them to hold it up to the light.
6. Hold the message the light and voila! Your message will appear.

Explanation:

When you hold the paper up to the light, the lemon juice turns brown and the secret message appears. This is because lemon juice contains carbon atoms and molecules that break apart when exposed to light. Carbon is usually black or brown which is why you see the message when the lemon juice is heated.