LIFE DEPENDS ON THE UNIQUE PROPERITIES OF WATER

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• LIFE DEPENDS ON THE UNIQUE PROPERITIES OF WATER

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Physical Properties- can be observed and measured

• Water is a form of matter
• Matter- anything that occupies space and has mass

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What happens when you put an ice cube in a glass
of water?

• Why????
• What do you think would happen to a can of coke
  and diet coke if we placed it into a container of
  water? Float? Sink? Why?

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THE STRUCTURE OF WATER

• Made up of two covalently bonded hydrogen atoms
  to an oxygen atom
• Polar Molecule- a molecule that has opposite ends
  with opposite charges

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THE STRUCTURE OF WATER

• Hydrogen Bond- weak attraction, bond between a
  hydrogen atom of a molecule and a slightly
  negative atom within another molecule.

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WATERS LIFE SUPPORTING PROPERTIES

• Cohesion
• Adhesion
• Temperature Moderation
• Low Density of Ice
• Waters Ability to Dissolve Other Substances

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COHESION AND ADHESION

• Cohesion- the tendency of molecules of the same
  kind to stick to one another
• Adhesion- an attraction between unlike molecules

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COHESION AND ADHESION

• Example water transport of trees/plants
• Evaporation pulls water which are attached by
  cohesion up from the roots.
• Adhesion of water to the walls of veins resist
  the downward pull of gravity

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Drops On a Penny

• How many drops fit on the penny?
• Explain the bubble that forms on penny

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COHESION AND ADHESION

• Surface Tension- cohesion which pulls the
  molecules at the surface tightly together

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When have you experienced surface tension?

• http//www.youtube.com/watch?v6eh93mut9K4feature
  relmfu

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Basilisk Lizard

• http//www.youtube.com/watch?v45yabrnryXkfeature
  fvw
• http//www.teachertube.com/viewVideo.php?video_id
  96527

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TEMPERATURE MODERATION

• Thermal Energy- total amount of energy associated
  with the random movement of atoms and molecules
  in a sample of matter.
• Temperature- a measure of energy of random motion
  of particles in a substance

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TEMPERATURE MODERATION

• When two substances differ in temperature,
  thermal energy in the form of heat is transferred
  from the warmer substance to the cooler one

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TEMPERATURE MODERATION

• When you heat molecules move faster
• When you cool molecules move slower
• Water takes more energy to heat because of
  hydrogen bonds
• Water retain heat longer because of hydrogen bonds

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LOW DENSITY OF ICE

• Density- amount of matter in a given volume
• In most substances the solid state is more dense
  than the liquid state

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LOW DENSITY OF ICE

• Waters solid state is LESS dense than the liquid
  state
• WHY?????
• Hydrogen bonds in ice (solid) keep molecules
  spaced out

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LOW DENSITY OF ICE

• Since ice is less dense than water it floats
• Ice prevents oceans from freezing over
• Ice insulates the liquid water below allowing
  life to persist

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WATERS ABILITY TO DISSOLVE OTHER SUBSTANCES

• Solution- a uniform mixture of two or more
  substances
• Solvent- the substance that dissolves the other
  substance and is present in greater amounts
  (water)
• Solute- the substance that is dissolved, present
  in a lesser amount (salt)

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WATERS ABILITY TO DISSOLVE OTHER SUBSTANCES

• Aqueous Solution- when water is the solvent
• Water molecules surround ions and break them apart

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WATERS ABILITY TO DISSOLVE OTHER SUBSTANCES

• Water is the Universal Solvent
• Water is the main solvent inside all cells,
  blood, and plant sap

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Wrap Up!

• http//www.youtube.com/watch?vQH1yphfgfFI
• Structure of Water Molecule Bent. Why?
• 5 Unique Properties of Water
• 1. Cohesion
• 2. Adhesion
• 3. Temperature Moderation
• 4. Low Density of Ice
• 5. Waters Ability to Dissolve other Substances

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Exit Slip

• 1. Explain how the structure of water molecules
  results in attractions among them.
• 2. Give an example of how cohesion among water
  molecules is important to living things.
• 3. Explain one way in which water can moderate
  temperature.