What do these two changes have in common?
baking cookies
burning a marshmallow over a campfire

 - Both are caused by cooling.
 - Both are caused by heating.
 - Both are only physical changes.
Step 1: Think about each change.
Baking cookies is a chemical change. The type of matter in the cookie dough changes when it is baked. The cookie dough turns into cookies!
Burning a marshmallow is a chemical change. The heat from the fire causes the type of matter in the marshmallow to change. The marshmallow becomes black 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.