Ask Jimmy and the Bug
art by Dean Stanton, text by Ellen Braaf
Let me show you!
- What is a reagent?
[anno: A reagent is a chemical that is combined with another chemical.]
- Why is the appearance of invisible ink on a piece of paper a chemical change? Tell how you know this is a chemical change.
[anno: The appearance of invisible ink is a chemical change because it involves heating a piece of paper to make the ink appear. The ink is actually burning, which causes it to change color.]
- A spy soaks a shoelace in water to create an invisible ink. Do you think the creation of the invisible ink is a chemical change or a physical change? Why? Write a sentence or two to explain your answer.
[anno: The creation of an invisible ink by soaking a shoelace in water is a physical change. The shoelace has not changed, and the water has not changed. The two substances have just been mixed together.]