WaterWater

How Unique is Water??How Unique is Water??

Water is one of only 3 naturally occurring Water is one of only 3 naturally occurring inorganic liquidsinorganic liquids

Only chemical compound that naturally Only chemical compound that naturally exists in all 3 states—solid, liquid, and gasexists in all 3 states—solid, liquid, and gas

Why is Water Important?Why is Water Important?

Can dissolve just about anythingCan dissolve just about anything

Liquid water can carry substances around Liquid water can carry substances around cells, organisms, ecosystems, or the cells, organisms, ecosystems, or the planetplanet

Oceans help to moderate Earth’s Oceans help to moderate Earth’s temperaturetemperature

Water is a polar compound…Water is a polar compound…

Shares e- unevenlyShares e- unevenly

Oxygen atom has a slight - charge, the Oxygen atom has a slight - charge, the Hydrogen atoms take on a slight + chargeHydrogen atoms take on a slight + charge

http://programs.northlandcollege.edu/http://programs.northlandcollege.edu/biology/Biology1111/animations/biology/Biology1111/animations/hydrogenbonds.htmlhydrogenbonds.html

It is water’s polarity that gives It is water’s polarity that gives it many of its unique it many of its unique

properties…properties…

Hydrogen BondingHydrogen Bonding

Results from attraction between + & -Results from attraction between + & -

Water can form H-bonds with up to 4 Water can form H-bonds with up to 4 neighboring water moleculesneighboring water molecules

In liquid water, H bonds form and break In liquid water, H bonds form and break quicklyquickly– http://www.visionlearning.com/library/http://www.visionlearning.com/library/

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In solid ice, H bonds lock water molecules In solid ice, H bonds lock water molecules in placein place– http://www.visionlearning.com/library/http://www.visionlearning.com/library/

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What happens when water evaporates??What happens when water evaporates??

Extremely large liquid range (0Extremely large liquid range (0ooC - 100C - 100ooC)C)

Expands, becomes less dense as a solidExpands, becomes less dense as a solid

CohesionCohesionWater molecules have a strong tendency Water molecules have a strong tendency to stick to one anotherto stick to one another

Cohesion allows water to have a high Cohesion allows water to have a high degree of surface tensiondegree of surface tension– Any force is transmitted to the column of Any force is transmitted to the column of

water as a wholewater as a whole

AdhesionAdhesion

Ability of water to stick to other substances, Ability of water to stick to other substances, esp. charged atoms or moleculesesp. charged atoms or molecules

Together, cohesion and adhesion allow for Together, cohesion and adhesion allow for capillary actioncapillary action