ethan is observing chemical and physical properties of a substance. he heats a substance and observes that…

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?\na by demonstrating that the substance will eventually melt if the temperature continues to increase\nb by verifying that the substance is now made up of different molecules than before it was heated\nc by verifying that the substance is made up of only one type of element\nd by demonstrating that the substance is less dense after it is heated

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?\na by demonstrating that the substance will eventually melt if the temperature continues to increase\nb by verifying that the substance is now made up of different molecules than before it was heated\nc by verifying that the substance is made up of only one type of element\nd by demonstrating that the substance is less dense after it is heated

Answer

Brief Explanations:

A chemical change involves a change in the chemical composition of a substance, which means different molecules are formed. Melting is a physical change, verifying a single - type element doesn't prove a chemical change, and change in density is a physical property change.

Answer:

B. by verifying that the substance is now made up of different molecules than before it was heated