Question

A man makes breakfast. He puts some toast in the toaster, and mixes some eggs with a little milk in a bowl. As he begins cooking the eggs, he smells the toast burning. He takes the toast out of the toaster and puts some butter on it, which melts. Finally, he pours some orange juice through a strainer to remove the pulp. He eats the meal, and he digests it as he drives to work in his car. Which option correctly identifies a chemical and a physical change in the scenario?

Answer 1

In the scenario, the correct identification of a chemical change and a physical change would be:

• Chemical Change: Cooking the eggs. When the eggs are heated, they undergo a chemical change as the proteins in the eggs denature and coagulate, transforming from a liquid to a solid.

• Physical Change: Melting the butter on the toast. When butter is heated, it changes from solid to liquid, which is a physical change as it does not alter the chemical composition of the butter.

Thus, the cooking of the eggs represents a chemical change, while melting butter is a physical change.