The Properties of WaterThe Properties of Water

The Mickey Mouse Molecule!

HydrogenHydrogen

Oxygen

Structure of a Water Structure of a Water MoleculeMolecule

• Water is Water is polar.polar.•A polar molecule is a molecule that A polar molecule is a molecule that

has an has an electricalelectrical charge. charge.•Water is made of:Water is made of:

• 2 2 HydrogenHydrogen Atoms and 1 Atoms and 1 OxygenOxygen atom. atom.• The chemical formula for water is:The chemical formula for water is:

HH22OO• Hydrogen has a Hydrogen has a positive (+)positive (+) charge charge

and Oxygen has a and Oxygen has a negative (-)negative (-) charge. charge.

4 Key Properties of Water4 Key Properties of Water

•Capillary ActionCapillary Action

•Surface TensionSurface Tension

•Universal SolventUniversal Solvent

•Specific HeatSpecific Heat

Capillary ActionCapillary Action• Capillary action Capillary action is the combined force of is the combined force of

attraction among attraction among water molecules water molecules and and with the molecules of with the molecules of surrounding surrounding materials.materials.

• Examples of Capillary Action of Water:Examples of Capillary Action of Water:– Liquid rising inside a strawLiquid rising inside a straw– Paper towel absorbing waterPaper towel absorbing water– Wet jeansWet jeans– Plant roots absorbing waterPlant roots absorbing water– SpongeSponge

Surface TensionSurface Tension

• Surface tension Surface tension is the is the tightness tightness across the across the surface of water that is caused by the surface of water that is caused by the polar polar molecules molecules pulling on one anotherpulling on one another

• Examples of the surface tension of Examples of the surface tension of water:water:– Raindrops forming beads on surfaceRaindrops forming beads on surface– Water striderWater strider– Paperclip Floating on WaterPaperclip Floating on Water– Drops of Water on a PennyDrops of Water on a Penny– Skipping RocksSkipping Rocks– MeniscusMeniscus– Belly FlopsBelly Flops

Jesus LizardJesus Lizard

My real name is the “Green Basilisk Lizard

“....

But not like the one from Harry

Potter!!!

Water StriderWater Strider

Universal SolventUniversal Solvent

• SolutionSolution: A : A mixturemixture that forms when that forms when one substance dissolves another.one substance dissolves another.

• SolventSolvent: substance that does the : substance that does the dissolving.dissolving.

• SoluteSolute: substance that gets dissolved.: substance that gets dissolved.– Water is the universal solvent because it dissolves so Water is the universal solvent because it dissolves so

many substances because of its high polarity.many substances because of its high polarity.– Water can dissolve substances such as salt and sugar but Water can dissolve substances such as salt and sugar but

cannot dissolve oilcannot dissolve oil..- - Polar Dissolves Polar Dissolves Polar.Polar.

Specific HeatSpecific Heat• Water requires a lot of heat (gain or loss) to change its temperature due to the strong attraction among water molecules.Water requires a lot of heat (gain or loss) to change its temperature due to the strong attraction among water molecules.• Specific heatSpecific heat is the amount of heat needed to increase the temperature of a substance by is the amount of heat needed to increase the temperature of a substance by 1100CC• Example of specific heat:Example of specific heat:

-- Water Water temperature temperature vs. sand vs. sand temperature temperature at the beach at the beach during the during the day.day.

Why does water have a high Why does water have a high specific heat?specific heat?

– Water’s high specific heat is due to Water’s high specific heat is due to thethe strong attraction among strong attraction among water molecules.water molecules.

– The molecules areThe molecules are stuck stuck togethertogether and it takesand it takes a lot of a lot of energyenergy to break the strong to break the strong bonds of the water molecules.bonds of the water molecules.

Changing StateChanging State• Water exists in 3 forms: Water exists in 3 forms:

– solidsolid– liquid liquid – gasgas

solid liquid gas

Molecule MovementMolecule MovementMolecules move the Molecules move the

slowestslowest in a in a solid.solid.Solid-molecules are Solid-molecules are

close togetherclose together

Molecules move the Molecules move the fastestfastest in a in a gas.gas.

Gas-molecules move Gas-molecules move freely; they are freely; they are spread apartspread apart

Phase ChangesPhase Changes

• MeltingMelting-water changes from a solid -water changes from a solid to a liquidto a liquid– Example: Ice melts into waterExample: Ice melts into water

• FreezingFreezing-water changes from a liquid -water changes from a liquid to a solidto a solid– Example: Example: Water freezes into iceWater freezes into ice

Melting

FreezingSolid Liquid

Phase ChangesPhase Changes• EvaporationEvaporation- process by which molecules at - process by which molecules at

the surface of a liquid absorb enough the surface of a liquid absorb enough energy to change to the gaseous stateenergy to change to the gaseous state– Example: Example: boiling water, hair air-dryingboiling water, hair air-drying, , wet wet

clothes drying on a clothesline outside, puddle clothes drying on a clothesline outside, puddle drying updrying up

• CondensationCondensation-process by which a gas -process by which a gas changes to a liquidchanges to a liquid– Example: water droplets on the outside of a Example: water droplets on the outside of a

glassglass

fogging up a windowfogging up a windowLiquid Gas

Evaporation

Condensation

Phase ChangesPhase Changes

Phase Change DiagramPhase Change Diagram