Question

1. classify each change as physical or chemical. a. crushing an aluminum can b. recycling used aluminum cans to make new ones c. aluminum combining with oxygen to form aluminum oxide

Explanation:

Step1: Define physical change

A physical change alters form or appearance without changing chemical composition.

Step2: Analyze crushing an aluminum can

Crushing only changes shape, not chemical makeup. So it's a physical change.

Step3: Analyze recycling used aluminum cans to make new ones

Melting and reforming are physical processes, no new substances formed chemically. So it's a physical change.

Step4: Analyze aluminum combining with oxygen

A chemical reaction occurs forming a new substance (aluminum oxide). So it's a chemical change.

Answer:

a. Physical change
b. Physical change
c. Chemical change