what is the origin of the material that collects on the surface of windows when you breathe on it?

Question

you know the fog you see after you breathe on an window, where does this moisture come from?

Answer 1

the moisture is the water that is in the air we breath. when you breath it in, you warm up the air - when you breath on the window, the window is colder than the air you breath out. cold air can hold less moisture than warm, so the moisture condenses out onto the window - forming a fog.

clouds, mist and fog occur when the water vapour (the moisture) in the air condenses out - usually when the temperature drops such as when air blowing from the sea rises over mountains

if you live somewhere cold, when you breath out you can see a fog in the air - same thing

Answer 2

every breath exhaled by humans contains water vapor. this is very obvious to people that live in cold climates as you can see your breath when it gets cold.

Anytime you have water vapor and a temperature difference, condensation is possible- the air you blow on a window is a 98 degrees or maybe a little less but usually 20-30 degrees warmer than a room temperature window pane. The water vapor in the breath condesnses on the colder window pane.

Answer 3

When you breath out your breath contains moisture, also if the window is cold your breath will warm the window and water vapor in the air will condense on the window.