Question

which scenario is an example of a physical change?
wood is burned in a campfire and is turned into ash and smoke.
a piece of metal is left in the rain and forms rust.
lead is melted into a liquid to form pellets.
yeast turns sugar into energy, water, and carbon dioxide gas.

Explanation:

To determine a physical change, we recall that physical changes involve a change in state or appearance without forming new substances.

• Burning wood (first option) produces ash/smoke (new substances) – chemical change.
• Metal rusting (second option) forms rust (new substance, iron oxide) – chemical change.
• Melting lead (third option) changes it from solid to liquid (state change, no new substance) – physical change.
• Yeast fermenting sugar (fourth option) produces new substances (energy, water, CO₂) – chemical change.

Answer:

C. Lead is melted into a liquid to form pellets.