Magical invisible ink
You will need:
- A plastic measuring spoon
- One sheet of white A4 paper
- Cotton swabs
- Water and grape juice
- Baking soda
- A small 30cc cup
- A spray can.
- Pour out 10cc of water into a the small 30cc cup.
- Measure out the baking soda, using the 1g plastic measuring spoon, and then pour it into the small 30cc cup. Stir the baking soda into the water with a cotton swab until the resulting mixture has an even consistency.
- Dip another cotton swab into the mixture of baking soda and water that is in the cup.
- Gently write a few words onto the sheet of white A4 paper.
- Allow the words to dry onto the paper.
- Finally, fill the spray can with grape juice, spray the grape juice over the words on the paper, and watch as the magic happens: all of the written words start to appear!
How it works:
When alkaline baking soda is mixed with acidic grape juice, the anthocyanins in the grape juice change as the pH fluctuates. Therefore, the alkaline baking soda liquid that was used for the writing changes color when it is combined with the grape juice.
＊Resource come from: NTCU Science Game Lab.