What do these two changes have in common?
crushing a mineral into powder
mixing lettuce and salad dressing
A: Both are only physical changes.
B: Both are caused by heating.
C: Both are chemical changes.
D: Both are caused by cooling.
Step 1: Think about each change.
Crushing a mineral into powder is a physical change. The mineral breaks into tiny pieces. But it is still made of the same type of matter.
Mixing lettuce and salad dressing is a physical change. Together, the salad and dressing make a mixture. But making this mixture does not form a different 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.