Final answer:
Materials need to undergo chemical changes to be recycled. This involves altering their chemical composition to create new items, which is a key process in recycling.
Step-by-step explanation:
To answer the student's question, in order for materials to be recycled, they must undergo chemical changes to transform. Recycling involves processing used materials to make them suitable for reuse, which typically means breaking down the original material and using the resulting substances to create new items. This process often involves altering the chemical composition of the material to be recycled.
For example, when paper is recycled, it is not simply cut into smaller pieces (which would be a physical change); instead, the fibers are broken down using chemicals or heat, which is a chemical change. Similarly, plastics are often melted and reformed, and glass is melted to be remolded, both of which also involve chemical changes in the material's structure during the recycling process.