Question

the table lists two experiments performed using aluminum foil.

experiment	description	observation
2	heat aluminum foil and lemon juice in the oven.	the aluminum foil changes color where the lemon juice has come in contact.

what types of changes are observed in the two experiments?

• experiment 1 shows a chemical change because the aluminum curls up due to heat. experiment 2 shows a physical change because a new substance forms on the aluminum.
• experiment 1 shows a physical change because the aluminum curls up due to heat. experiment 2 shows a chemical change because a new substance forms on the aluminum.
• both experiments show a physical change because no new substance is formed.
• both experiments show a chemical change because the properties of the aluminum change.

Explanation:

A physical change alters form/appearance without new substances; a chemical change forms new substances. In Experiment 1, heating only softens/curls aluminum (no new substance, physical change). In Experiment 2, lemon juice reacts with aluminum to create a color change from a new substance (chemical change).

Answer:

Experiment 1 shows a physical change because the aluminum curls up due to heat.
Experiment 2 shows a chemical change because a new substance forms on the aluminum.