Question

question 7. which of the following statements are true about physical and chemical changes? (select all that apply) as heat is added to ice, it melts and becomes liquid water. this is an example of a physical change a chemical change forms new substances. a physical change alters the appearance but not the chemical composition. crushing an aluminum can is an example of a chemical change. aluminum combining with oxygen to form aluminum oxide is an example of a physical change.

Explanation:

1. Melting of ice is a physical change as only the state changes, not the chemical composition (H₂O remains H₂O).
2. Chemical changes result in new substances due to chemical reactions.
3. Physical changes like changing shape or state only affect appearance without altering chemical makeup.
4. Crushing an aluminum can is a physical change as no new substance is formed.
5. Aluminum combining with oxygen to form aluminum oxide is a chemical change as a new compound is formed.

Answer:

A. As heat is added to ice, it melts and becomes liquid water. This is an example of a physical change
B. A chemical change forms new substances.
C. A physical change alters the appearance but not the chemical composition