Properties of Water ETO

Properties of Water Polar Adhesion Cohesion Capillary Action Surface Tension http://www.bing.com/videos/search?q=properties+of+water&FORM=HDRSC3#view=detail&mid=D33C8999E51DBE506B78D33C8999E51DBE506B78

Water molecules are held together by hydrogen bonds…. Water (H2O) Polar Covalent- * Polarity + + _ Water molecules are held together by hydrogen bonds….

Universal Solvent- able to dissolve many substances because of its polarity. Solvent-Liquid Solute -Solid

Non- Polar doesn’t mix… WAXY Cuticle Lipids are non-polar

Is waters reaction Polar or Non-Polar + - - + Polar molecules will react will other polar molecules. (Ex- Paper and Water.) * they will show an attraction. Polar molecules will not react with non- polar molecules. (Ex: Oil and Water) * they will not show an attraction. + -

Polar or Non-Polar

* It allows drops to form…. Cohesion- water sticking to water Adhesion- water sticking to something else. * It allows drops to form….

ADHESION COHESION

Surface Tension Surface tension: Caused by the cohesion of water molecules. Since Individual molecules are more attracted to each other than to the surrounding air.

Surface tension- water forms a film on the surface.

Helps insects walk across water Surface Tension Surface Tension Lighter than Hydrogen Bonds Helps insects walk across water

Capillary action- pulling of water up…. Adhesion and Cohesion http://www.youtube.com/watch?v=y-h_qGhgtno

Capillary Action in Carnations Adhesion and Cohesion

As water freezes, its molecules spread apart making frozen water less dense than liquid water. * So it floats……. LATTICE http://www.youtube.com/watch?v=sQdLttUh_b0

Water is Less Dense as a Solid Ice is less dense …. That’s why ice floatsas a solid than as a liquid (ice floats) LATTICE 1

Forms a Insulating Barrier Why is it important that ice float to life on the planet? Forms a Insulating Barrier

High Specific Heat Capacity- ability to maintain a temperature. * Water takes longer to heat up, and losses the heat slower. * Temperatures in deserts- Day- Hot Night-Cold Why?

Heat Capacity (High) Water changes temp very slowly because it can store heat. This protects living organisms from the shock of abrupt temperature changes. Helps control the world’s climate.

How polarity makes water behave strangely - Christina Kleinberg

1. Water dissolves many substances. This occurs because water has- A. surface tension B. polarity C. specific heat D. cohesion

2. When the cells of most organisms freeze, they burst. A. Water is a universal solvent. B. Water changes temperature rapidly. C. Water is less dense as a solid than as a liquid. D. Water is a nonpolar molecule. Which property of water causes this to occur?

3. Some adult insects are unable to swim but are able to walk on top of water. What characteristic of water enables these insects to walk on top of water? A. pH B. surface tension C. solvent properties D. atomic bonds

4. When water dissolves a substance, weak charges carried by water molecules attract the substance’s oppositely charged atoms and pull them away from their molecules. This is a function of which property of water? A. pH B. polarity C. cohesion D. surface tension

5. Ice floats on a lake. This characteristic of water is responsible for — A. suffocation of aquatic organisms B. mixing a lake’s thermal layers C. preventing a lake from freezing solid D. altering migration patterns of fish

A. Water expands as it freezes. B. Water is an excellent solvent. 6. Water is essential for life. Its special properties make water the single most important molecule in plant life. Which of the following properties of water enables it to move from the roots to the leaves of plants? A. Water expands as it freezes. B. Water is an excellent solvent. C. Water exhibits cohesive behavior. D. Water is able to moderate temperatures. Water Cycle Important

7. Large bodies of water, such as lakes and oceans, do not quickly fluctuate in temperature. What is the reason for this phenomenon? A. Water is an acid. B. Water is a versatile solvent. C. Water has a high heat capacity. D. Water acts as a buffer.

Forms a Insulating Barrier 8. Why does ice stay at the top of oceans instead of sinking to the bottom? A. Ice is colder than liquid water. B. Ice is less dense than liquid water. C. Ice is more dense than liquid water. D. Ice is warmer than liquid water. Forms a Insulating Barrier

10. A scientist believes that a factory has been dumping acid into a local river. To test this hypothesis, which property of water should the scientist monitor? A. pH B. density C. polarity D. temperature

Properties of Water Polar Adhesion Cohesion Capillary Action Surface Tension

Definition of Property Relates to everyday life Property of Water Definition of Property Relates to everyday life Sketch Polarity Cohesion Adhesion Capillary Action Surface Tension Heat Capacity Freezing anomoly Have students brainstorm as a group from the following slides to fill in the chart. Copy in notebook

Polarity Cohesion Adhesion Capillary Action Surface Tension Property of Water Definition of Property Relates to everyday life Pictures Polarity Having positive and negative charge. Ability to dissolve substances Student sketches may vary Cohesion Water sticks to itself Form drops and surface tension Adhesion Water sticks to other objects Allows for capillary action Capillary Action ability of a liquid to flow in narrow spaces Transfers water from roots to leaves (transpiration) Surface Tension Forms a film on surface Allows things (insects) to float on water. High Heat Capacity of heat required to change its temperature Moderates temperature changes. Ex: Bodies of water. Freezing anomaly Expands as it freezes May cause cells to rupture. Prevents lake from freezing solid.