Which statement correctly describes a physical change?

Which statement correctly describes a physical change?

• A. Melting ice is a physical change because it is still H2O
• B. Burning wood is a physical change
• C. Melting ice is a chemical change
• D. Boiling water is a chemical change

Answer: (A)

A physical change is a transformation that alters a substance’s form or state without changing its identity. Melting ice to liquid water fits this: the substance remains H2O, but its state changes from solid to liquid, and no new substance is formed. That’s why the statement describing melting ice as a physical change because it is still H2O is the correct one. Burning wood, on the other hand, is a chemical change, because combustion breaks bonds and creates new substances such as ash, carbon dioxide, and water vapor. Melting ice being labeled as a chemical change is incorrect for the same reason—no new substance is produced in this phase change. Boiling water is also a physical change, since it’s just a state change from liquid to gas, with H2O still the same substance.

A physical change is a transformation that alters a substance’s form or state without changing its identity. Melting ice to liquid water fits this: the substance remains H2O, but its state changes from solid to liquid, and no new substance is formed. That’s why the statement describing melting ice as a physical change because it is still H2O is the correct one.

Burning wood, on the other hand, is a chemical change, because combustion breaks bonds and creates new substances such as ash, carbon dioxide, and water vapor. Melting ice being labeled as a chemical change is incorrect for the same reason—no new substance is produced in this phase change. Boiling water is also a physical change, since it’s just a state change from liquid to gas, with H2O still the same substance.