What do these two changes have in common?
baking an apple pie
rust forming on a metal gate

 - Both are only physical changes.
 - Both are chemical changes.
 - Both are caused by heating.
 - Both are caused by cooling.
Step 1: Think about each change.
Baking an apple pie is a chemical change. The type of matter in the pie changes. The apples become soft, and the crust turns brown.
Rust forming on a metal gate is a chemical change. As the gate rusts, the metal turns into a different type of matter called rust. Rust is reddish-brown and falls apart easily.
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.
Baking is caused by heating. But rust forming on a metal gate is not.
Both are caused by cooling.
Neither change is caused by cooling.