Question

question 4 (1 point)
a student notices that when he breathes out on a cool window, the water vapor (gas) in his breath forms liquid water droplets. what happens to heat
the water vapor in his breath into liquid water?
o a the water molecules become more spread apart as they touch the window
o b heat is added to the water vapor from the surrounding air
o c the temperature of the water vapor increases as it leaves his body
o d heat leaves the water vapor as it touches the cool window

Explanation:

When water vapor (gas) turns into liquid water (a process called condensation), heat is released. In this case, the water vapor in the breath loses heat when it touches the cool window.

• Option a: In a gas, molecules are more spread apart. When forming a liquid (condensation), molecules get closer, so this is incorrect.
• Option b: Heat is not added. Condensation is an exothermic process (heat is released), so this is incorrect.
• Option c: The temperature of the water vapor decreases as it loses heat during condensation, so this is incorrect.
• Option d: Heat leaves the water vapor (gas) as it condenses into liquid water droplets on the cool window. This is correct.

Answer:

d. Heat leaves the water vapor as it touches the cool window.