Which statement correctly identifies a clue of a physical change?

Which statement correctly identifies a clue of a physical change?

• A. State changes
• B. Dissolving
• C. Form changes
• D. Color change

Answer: (A)

State changes show a physical change because they involve a shift in how particles are arranged and how much energy is in the system without altering what the substance is. When a solid becomes a liquid or a liquid becomes a gas, the substance stays the same chemically; only its phase changes. Dissolving is often a physical change, but it isn’t always definitive since some dissolving involves chemical reactions that form new substances. A change in form like tearing or reshaping is also physical, but it’s not as universally recognizable as a clue as a change in state. Color change can accompany either physical or chemical changes, so it isn’t a reliable indicator of a physical change on its own. So, state changes are the clearest clue that a physical change has occurred.

State changes show a physical change because they involve a shift in how particles are arranged and how much energy is in the system without altering what the substance is. When a solid becomes a liquid or a liquid becomes a gas, the substance stays the same chemically; only its phase changes. Dissolving is often a physical change, but it isn’t always definitive since some dissolving involves chemical reactions that form new substances. A change in form like tearing or reshaping is also physical, but it’s not as universally recognizable as a clue as a change in state. Color change can accompany either physical or chemical changes, so it isn’t a reliable indicator of a physical change on its own. So, state changes are the clearest clue that a physical change has occurred.