Step 1: Think about each change.
Water vapor condensing on a bathroom mirror is a change of state. So, it is a physical change. The water changes state from gas in the air to liquid water on the mirror. But the water vapor and the liquid water are both made of water.
Loose matter such as sand and dirt is called sediment. Sediment settling to the bottom of a muddy puddle is a physical change.
The sediment sinks, and the water above becomes clearer. This separates the water from the sediment. But separating a 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.
Water vapor condensing is caused by cooling. But sediment settling to the bottom of a muddy puddle is not.
What do these two changes have in common?
water vapor condensing on a bathroom mirror
sediment settling to the bottom of a muddy puddle
A: Both are caused by cooling.
B: Both are caused by heating.
C: Both are only physical changes.
D: Both are chemical changes.