Water droplets that formed from cooled water vapor in your breath Carbon dioxide that you are breathing out from your lungs Oxygen that you are breathing out from your lungs Cooled nitrogen in the air around you
I gave my students this multiple choice question: If you breathe on a mirror, part of the mirror clouds up. What are you actually seeing when you see the mirror cloud up?

Only one answer is correct among these 4 choices:
- Water droplets that formed from cooled water vapor in your breath
- Carbon dioxide that you are breathing out from your lungs
- Oxygen that you are breathing out from your lungs
- Cooled nitrogen in the air around you

Could you tell me which one is correct?

Water droplets that formed from cooled water vapor in your breath