Science Buddies: "Ask an Expert"

For his 4th grade science project, my son will basically set up a water cycle in a jar experiment using cold, warm and hot water. It will demonstrate that the warmer the temperature of the water, the faster the water cycle occurs, starting with evaporation and then condensation. Just want to confirm that our reasoning is correct: HOT water molecules move faster and therefore evaporate faster. So the hot water jar collects more water vapor in a shorter period of time, resulting in a more humid air, higher concentration of water vapor results in a quicker formation of condensation?

Hi ylevin,

I think you are explaining it well. See this link for more details: https://www.reference.com/science/tempe ... fdaeb2350c#

Here is the info copied directly from the answer on that site:

Evaporation, a necessary component of the Earth's water cycle, takes place when a substance changes states of matter from a liquid into a gas. Several factors affect the rate of evaporation, and temperature is one of the major ones. With an increase in temperature, a direct increase in kinetic energy at the surface of the liquid takes place. The molecules in the liquid begin to move faster, colliding with one another at an increasing rate until some of the molecules escape into the atmosphere as water vapor. Other factors affecting evaporation rate include humidity, the nature of the liquid, the amount of wind present and the surface area of the liquid. Conditions that speed the rate of evaporation, in addition to higher temperature, include an increase in wind, an increase in surface area and a decrease in humidity. Ideal conditions for evaporation include dry hot air surrounding a hot liquid with a large surface area.

I hope this helps.

Tonya