When water vapor cools, it undergoes condensation, which is the process of changing from a gas to a liquid state. As water vapor molecules lose heat energy to a cooler surface or cooler air, they slow down, and the attractive forces between them cause the molecules to come together and form liquid water droplets

. This cooling typically occurs when the temperature drops below the dew point-the temperature at which the air becomes saturated with water vapor and can no longer hold it in the gas phase. At or below this temperature, water vapor condenses into tiny liquid droplets, which can form dew on surfaces, clouds in the atmosphere, or fog near the ground

. In the atmosphere, condensation is a key part of the water cycle. Water vapor condenses on particles in the air (cloud condensation nuclei), forming clouds. The energy released during condensation (latent heat) warms the surrounding air, which can cause air to rise and promote further condensation and cloud formation. Eventually, condensed water droplets can combine and fall as precipitation, continuing the water cycle

. In summary, when water vapor cools:

• It loses energy and slows down.
• Molecules come closer and stick together.
• The gas changes into liquid water droplets (condensation).
• This process is fundamental to cloud formation, dew, fog, and precipitation in the water cycle