Properties of Water Honors Science

What is the formula for water? What are some properties that make water unique?

Simply Science: Water's Physical Properties. United Learning. 1998 Simply Science: Water's Physical Properties. United Learning. 1998. unitedstreaming. 2 March 2006 <http://www.unitedstreaming.com/>

Complete your “Water Notes” using: PowerPoint Notes USGS Web Link There will be “Quick Check” on this review content

What is WATER? Only substance that naturally occurs on Earth in all 3 states -Solid-Ice -Liquid-Water -Gas-Steam or Vapor 1 Oxygen and 2 Hydrogen atoms Partial Polar COVALENT bond

H H O Water is POLAR! Photo courtesy of: http://www.shorstmeyer.com/wxfaqs/float/watermolec.html

Why does water form droplets? Photo courtesy of: http://www.physicalgeography.net/fundamentals/8a.html

What does it look like just before the water spills off the penny? Use the medicine dropper to put as many drops of water as you can on the surface of your penny. How many drops fit? What does it look like just before the water spills off the penny? Why can the penny hold so many drops of water?

Surface Tension HYDROGEN bonds attract water molecules to each other They “stick” together This causes them to pile up on each other Photo courtesy of: http://www.biosurvey.ou.edu/okwild/misc/waterstrider.html

Photo courtesy of: http://www.shorstmeyer.com/wxfaqs/float/watermolec.html

Surface Tension Float a paperclip on top of a beaker of water Add a drop of soap and see what happens. What does the soap do to the water? Why? Photo courtesy of: http://www.biosurvey.ou.edu/okwild/misc/waterstrider.html

Capillary Action Dip the paper towel into the beaker of water. What happens to the water and the towel? Look at the graduated cylinder. What do you notice about the level of water next to the glass vs. the level of the water in the middle? Explain why.

Capillary Action Water molecules “stick” together. So…water molecules will “stick” together and can “climb” or travel through different substances.

Put the ice in the beaker of water. What happens to the ice? Density Put the ice in the beaker of water. What happens to the ice? Why? Observe the pot of boiling water? What is in the “smoke”? Why does it rise?

Density Describe the arrangement of the molecules of H2O in each of the three states of matter. What is the relative density of water in each of the three states of matter?

Solid Water... Photo courtesy of: http://www.physicalgeography.net/fundamentals/8a.html

Liquid Water... Photo courtesy of: http://www.physicalgeography.net/fundamentals/8a.html

Gaseous Water... Photo courtesy of: http://www.physicalgeography.net/fundamentals/8a.html

Why do bodies of water generally freeze only on the top?

Density Solid: particles are close together Liquid: particles are near each other Gas: particles are very spread apart Water is unique: Solid water is LESS dense than liquid water!!! The density of water reaches a max at 4oC and then begins to decrease as water gets colder!!!

Solubility Ability of a substance to dissolve in a liquid Water is polar; it can hold molecules in solution “Salts” readily dissolve in water because they have +/- charges Water is the UNIVERSAL SOLVENT Solubility can sometimes be changed with temperature

Specific Heat Why is the temperature of water often different from the temperature of nearby land?

Specific Heat Specific heat- amount of heat required to raise the temperature of 1 gram of a substance by 1oC Water can store an enormous amount of energy Water has a very high specific heat It must absorb much energy to increase in temp It must lose much energy to decrease in temp

change temperature gradually? Why do lakes and oceans change temperature gradually?