What do these two changes have in common?
pouring milk on oatmeal
sanding a piece of wood
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.
Pouring milk on oatmeal is a physical change. The oatmeal and milk form a creamy mixture. But making this mixture does not form a different type of matter.
Sanding a piece of wood is a physical change. The wood becomes smoother, but it is still made of the same type of matter.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are physical changes. No new matter is created.
Both are chemical changes.
Both changes are physical changes. They are not chemical changes.
Both are caused by heating.
Neither change is caused by heating.
Both are caused by cooling.
Neither change is caused by cooling.