Water evaporates when molecules at the interface of water and air have enough energy to escape the forces that hold them together in the liquid. Evaporation, along with boiling, is a type of vaporization.Continue Reading
Under normal conditions, a relatively small number of water molecules meet the parameters for evaporation. The kinetic energy of a molecule increases with temperature; this means evaporation rates are also higher with temperature. As temperature increases and more water molecules escape the surface of the water, the molecules beneath them lose energy and are less likely to contribute to further evaporation. This is evaporative cooling, and is the reason why sweating makes the body feel cooler. An increase in air movement also increases evaporation: A wet object dries faster on a windy day than on a still day.
The final contributing factor of evaporation is humidity. Just as some liquid water molecules transfer to the air, some water vapor molecules transfer back to the surface of the water. However, unless humidity is more than 100 percent, there are always more liquid molecules escaping to the air.
Evaporation is an important part of the water cycle. Water evaporating from Earth's water bodies enters the atmosphere where it condenses into clouds to later fall as rain. Overall, there is a balance between evaporation and precipitation.Learn more about Biology
Water boils when the thermal energy in the water, which is a type of kinetic energy which causes the water molecules to move around, exceeds the strength of the hydrogen bonds between the molecules, causing them to separate from the other molecules. This breaking of bonds between water molecules consumes any additional thermal energy added, so that water at boiling temperature does not increase in temperature until the phase change is complete. In normal conditions, much of the water vapor almost immediately turns to steam, which is actually composed of droplets of liquid water because it has left the source of heat.Full Answer >
Living things need air, food and water because they are essential to the chemical processes that provide organisms with energy and keep them alive. These processes are collectively known as metabolism. The nutrients found in food, the oxygen found in air and the solvent property of water are indispensable components of metabolism.Full Answer >
When chemical bonds in reacting molecules are broken during metabolism, energy is required, whereas chemical bonds in reacting molecules that form during metabolism will actually exert energy. During metabolism, the relative strengths of the bonds that are being broken and formed will influence the type of reaction that is happening and the likely results. In an exergonic reaction, energy is being released whereas in an endergonic reaction, energy is being absorbed.Full Answer >
Catabolic pathways break down molecules to release energy, while anabolic pathways use energy to create new molecules. Both types of pathways are important parts of an organism's metabolism.Full Answer >