Which of the following is an example of chemical change?
A)Copper building materials develop a green patina over time.
B)Water vapor condenses on the window.
C)Ethanol evaporates.
D)A mixture of hydrogen and oxygen gas explodes on ignition.
E)A helium balloon goes up in the air.

Question

Quizplus · Accepted Answer

A mixture of hydrogen and oxygen gas exploding on ignition is an example of a chemical change because the reactants (hydrogen and oxygen) are undergoing a chemical reaction that results in the formation of a new substance (water) with different chemical properties. The other choices are examples of physical changes, where the substance undergoes a change in state or appearance, but its chemical identity remains the same.

Which of the Following Is an Example of Chemical Change