What do these two changes have in common?
burning a candle
roasting a marshmallow over a campfire

 - Both are chemical changes.
 - Both are only physical changes.
 - Both are caused by cooling.
Step 1: Think about each change.
Burning a candle is a chemical change. Both the wick and the melted wax burn. They react with oxygen in the air and turn into soot, carbon dioxide, and water.
Roasting a marshmallow is a chemical change. The type of matter on the outside of the marshmallow changes. As a marshmallow is roasted, it turns brown and crispy.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are chemical changes. They are not physical changes.
Both are chemical changes.
Both changes are chemical changes. The type of matter before and after each change is different.
Both are caused by heating.
Both changes are caused by heating.
Both are caused by cooling.
Neither change is caused by cooling.