Why dew forms on cool mornings

Dew is made of liquid water that has condensed from some of the water vapor in the air. Dew occurs when objects cool. A common example of dew formation is when drops of liquid form on the glass of an ice-cold drink. Dew forms when the object, such as the glass, cools down to the dew point temperature.

Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening due to condensation. As the exposed surface cools by radiating its heat, atmospheric moisture condenses at a rate greater than that at which it can evaporate, resulting in the formation of water droplets. Dew drops are formed due to condensation of water vapours.

Air around contains humidity or moisture. The presence of humidity is more in hot air as compared to cold air. During the night when this hot air comes in the contact with cold surface, the humidity condenses to form the droplets which we call as dew drops. Dew is liquid water droplets that form on grass, spider webs, and other things in the early morning or late evening.

First, the air is cooled to the dew point which leads to the formation of fog droplets. When the sun rises, the air and ground warm up. This leads to the air temperature being warmer than the dew point temperature, which causes the fog droplets to evaporate. If skies then clear and wind is light, fog is very likely. Fog requires a mixing action by wind; without wind, dew will appear instead of fog. If the surface is near saturation, a light wind will allow for the layer of air near the surface to remain near saturation.

The dew point temperature is what causes dew to form on the grass in the morning. The morning, just before sunrise, is the lowest air temperature of the day, so it is the time when the dew point temperature is most likely to be reached.

The evaporation rate depends on the temperature of the water, which is the same temperature as the blades of grass. So, condensation depends on the state of the atmosphere, such as its temperature and moisture, while evaporation depends on the temperature of the object. If the object gets cold enough, and there is enough moisture in the air, condensation is much greater than evaporation and the film grows into dew drops.

Dew also tends to form on calm nights that come with clear skies. Windy conditions and cloudy skies keep the ground from cooling. The Weather Guys. Skip to content. Problem Snow Why does a pile of snow slowly shrink even o….

View Full Video Already have an account? Anna M. Problem 79 Easy Difficulty Explain why dew forms on cool mornings. Answer air's water vapor condenses upon contact with a cold object. View Answer. Topics Liquids Solids Gases. Discussion You must be signed in to discuss. Top Chemistry Educators Stephanie C. University of Central Florida. Stephen P. Drexel University. Morgan S. University of Kentucky. Karli S. Chemistry Bootcamp Lectures Liquids - Intro A liquid is a nearly incom…. Recommended Videos