Chemical changes involve atomic rearrangement

Steps:

• Define physical change: alters form without new substances, often reversible (e.g., melting ice).
• Define chemical change: forms new substances via bond breaking and forming (e.g., rusting).
• Compare options to definitions: A and B misapply to both types; D confuses reversal methods.
• Select C as it precisely describes chemical change process.

Why C is correct:

• Chemical changes rearrange atoms to break old bonds and form new ones, per the law of conservation of matter where atoms reorganize into different molecules.

Why the others are wrong:

• A: Physical changes do not produce new substances, only alter appearance.
• B: Physical changes are usually reversible, unlike most chemical changes.
• D: Physical changes reverse via physical means, like cooling to refreeze water.

Final answer: C