Ethan is observing chemical and physical properties of a substance. He heats a substance and observes that the substance turns from a brown solid to a black
powder. He refers to several chemistry journals that claim this represents a chemical
reaction. From his observation and research, he concludes that the substance goes
through a chemical change when heated. How can Ethan best defend his conclusion?
A. by demonstrating that the substance will eventually melt if the temperature
continues to increase
B. by verifying that the substance is now made up of different molecules than
before it was heated
C. by verifying that the substance is made up of only one type of element
D. by demonstrating that the substance is less dense after it is heated