What do these two changes have in common?
an iceberg melting slowly
baking cookies

 - Both are only physical changes.
 - Both are caused by heating.
 - Both are caused by cooling.
 - Both are chemical changes.
Step 1: Think about each change.
An iceberg melting is a change of state. So, it is a physical change. An iceberg is made of frozen water. As it melts, the water changes from a solid to a liquid. But a different type of matter is not formed.
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!
Step 2: Look at each answer choice.
Both are only physical changes.
An iceberg melting is a physical change. But baking cookies is not.
Both are chemical changes.
Baking cookies is a chemical change. But an iceberg melting is not.
Both are caused by heating.
Both changes are caused by heating.
Both are caused by cooling.
Neither change is caused by cooling.