Upload
vielka-diaz
View
47
Download
2
Embed Size (px)
DESCRIPTION
Water Properties SC.912.L.18.12. Water has unique properties that make it an important substance for life. Cohesion and Adhesion. Hkhkhjhkjhkh Cohesion is an attraction between substances of the same kind. - PowerPoint PPT Presentation
Citation preview
Water PropertiesSC.912.L.18.12
Water has unique properties that make it an important substance for
life.
Cohesion and Adhesion
Hkhkhjhkjhkh Cohesion is an attraction between substances of the same kind. Example: Hydrogen bonds between water molecules cause the cohesionof liquid water. Because of cohesion, water andother liquids form thin films and drops.
Adhesion• Adhesion is an attraction • between different substances.• Water molecules are attracted• to many other similarly polarized • substances• Example: Adhesion powers• capillary action, where H20 • molecules move upward thru• a narrow tube, such as the stem • of a plant.
Stores Heat Energy
• Water absorbs heat • more slowly and • retains this energy• longer than many other substances do. Many organisms releaseexcess heat through water evaporation.Example: Humans cool themselves by sweating.The water vapor lost through the evaporation of sweat carries heat away from the body.
Universal Solvent• Water has the ability to • dissolve many substances.• The polarity of water• enables many substancesto dissolve in water. Example: Ionic compounds and polar molecules dissolve best in water
Surface Tension• Water molecules• like to cling to one• another. At the • surface, there arefewer water molecules to cling since there is airabove (no water molecules). This results in a stronger bond between those molecules that actually do come in contact with one another and a layer of strongly bonded water.Example: Small insects such as the water strider can walk on water because their weight is not enough to penetratethe surface.
Review Questions:
Why is water a good solvent for many ionic compounds?
Water has the ability to store heat longer than other substances. What benefit does this property of water provide to organisms?