Which process is NOT considered a physical change?

Burning wood is the process that is not considered a physical change because it involves a chemical reaction. When wood burns, it undergoes combustion, producing ash, smoke, and various gases. This transformation alters the chemical structure of the wood, resulting in new substances that are different from the original material.

In contrast, melting ice, boiling water, and breaking glass are all examples of physical changes. These processes involve changes in the state or form of matter without altering its chemical composition. Melting ice turns solid water into liquid water, boiling water converts liquid water into steam, and breaking glass changes its shape without changing its chemical structure. Thus, the correct identification of burning wood as a non-physical change highlights the distinction between physical changes, which are reversible and do not affect the substance's chemical identity, and chemical changes, which result in the formation of new substances.