Question

1. the best friends club uses \invisible ink\ to write notes to each other. the invisible ink is actually lemon juice that is clear when it dries on paper but turns brown when a club member holds a burning candle under the paper. once it is heated, it is never invisible again.

what type of change is occurring when the paper is heated?
phase change
chemical change
elemental change
physical change
clear all

Explanation:

A chemical change produces a new substance and is irreversible. When lemon juice on paper is heated, it turns brown and cannot return to its original clear, invisible state, meaning a new substance is formed and the change is permanent. A physical/phase change is reversible and does not create new matter, while elemental change refers to altering chemical elements, which does not occur here.

Answer:

chemical change