<|system|>
Complete the sentence.
Water vapor condensing on a bathroom mirror is a ().
A: chemical change
B: physical change</s>.
<|user|>
Can you answer based on context?
<|assistant|>
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.