Question

You write an invisible message on paper with lemon juice - when you heat the paper, the writing turns brown. Chemical or physical change​

Answer 1

Writing with lemon juice and revealing the message through heating is a chemical change because it creates new substances with different properties.

Step-by-step explanation:

When you write a message on paper using lemon juice and then heat the paper to reveal the writing, you are observing a chemical change. The heat causes a reaction that alters the chemical composition of the lemon juice, resulting in a new substance with a different color. This is different from a physical change, which would involve a change in form or state without changing the substance's chemical identity. Unlike simply tearing a piece of paper, where the paper remains chemically the same, heating lemon juice on paper results in a complex reaction that includes oxidation and the breaking down of compounds, which makes it a chemical change. These types of changes usually produce new substances with properties different from those of the original substances, as seen with the brown coloring that appears.

Answer 2

Answer: Chemical Change.

Explanation: Lemon juice has properties that, when heated, turn the paper brown. In the invisible ink science experiment, that is why it is used. In lemon juice, the acid prevents peeled fruit from browning, like apples and pears. The lemon juice has a bitter taste and is acidic.