On a camping trip, Marta roasts a marshmallow in the campfire. The marshmallow grows, and then turns black. Marta notices that the roasted marshmallow smells and tastes differently than the uncooked marshmallows. What change has taken place, and how does Marta know?

Question

1. a chemical change because the marshmallow changed in taste, color and smell
2. no change because the marshmallow is not a new substance
3. only a physical change because the marshmallow changed size
4. a chemical change because the marshmallow only changed in pH level

Answer 1

The correct answer is:

1. a chemical change because the marshmallow changed in taste, color, and smell.

Marta observes that the roasted marshmallow has a different smell and taste, as well as a change in color when it turns black. These indicators show that a new substance has formed due to chemical reactions that occur during heating, such as caramelization and combustion.