What do these two changes have in common?
baking a loaf of bread
burning a candle

 - Both are caused by heating.
 - Both are caused by cooling.
 - Both are only physical changes.
Step 1: Think about each change.
Baking a loaf of bread is a chemical change. The type of matter in the dough changes when it is baked. The dough turns into bread!
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.
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.