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TheChemistryofLife

Chemistry

Chemistryisthefoundationof_____________________________.Everythingismadeupofmatterandmatteriscomposedof________________________________

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The Chemistry of Life

Chemistry is the foundation of _________________. Everything is made up of matter and matter is composed of _________________.

A. Properties of Protons, Neutrons and Electrons

Protons Neutrons Electrons Symbol

Charge

Location

Mass

Life requires about 25 elements. Four elements comprise 96% of living organisms. These 4 important elements include ______________, ___________________, ___________________, and ______________________. While 4 elements make up most of the remaining 4%; __________________________, ___________________________, _____________________, ______________________________.

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The Chemistry of Life

Chemistry is the foundation of _________________. Everything is made up of matter and matter is composed of _________________.

A. Properties of Protons, Neutrons and Electrons

Protons Neutrons Electrons Symbol

Charge

Location

Mass

Life requires about 25 elements. Four elements comprise 96% of living organisms. These 4 important elements include ______________, ___________________, ___________________, and ______________________. While 4 elements make up most of the remaining 4%; __________________________, ___________________________, _____________________, ______________________________.

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Life

Ê  Liferequiresabout25elements.Fourelementscomprise

96%oflivingorganisms.These4importantelements

include__________________,______________________,

___________________,and________________________.

Ê While4elementsmakeupmostoftheremaining4%;

_____________________,______________________,

_____________________,______________________.

Isotopes

Ê  Isotopesareatomsofanelementwiththesamenumberofprotons

butmaydifferinthenumberof__________________________.

Someoftheseisotopesareunstablemakingthemradioactiveand

manyoftheseradioisotopesareusefulinbiologyandmedicine.

Ê  Scientistscanuseisotopesof______________________toseehow

theyareconvertedinboth

Ê  ___________________________________andcellular

______________________________

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ElectronsandBonding

Ê  Electronsdeterminethe_________________propertiesofanatom.Thisisdependentuponthe___________________electronshellcalledthe_______________shell.Atomstendtocompletea________________filledvalenceshellor_______________apartiallyfilledvalenceshell.Rememberthatthe________________numberisequaltothenumberofprotonsandthenumberofprotonsisequaltothenumberof____________________.Electronsarecontainedwithinenergyshellssurroundingtheatomicnucleusandeachshellhasamaximumnumberofelectronsthatitcanhold.

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ValenceShells

Ê  Thefirstvalanceshellcanholdamaximumof______electrons.________and_______haveonevalanceshell.

Ê  Thesecondshellcanholdamaximumof______electrons.Whathappensasyoumovefromlefttorightinthesecondrowoftheperiodictable?

Ê  Thethirdshellcanholdamaximumof_______electrons.Asyoumovefromlefttorightthesamethinghappensasinthesecondrow.

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Use the periodic table above to answer the following. 1. What is the maximum number of electrons that each shell can hold?

1st Shell ___________ 2nd Shell __________ 3rd Shell ___________

Element Symbol # Protons # Neutrons #Electrons # Shells # Electrons in the valence shell

Carbon Hydrogen Oxygen Nitrogen Helium Argon

2. Compare the valence shell for C, H, O, and N. What do they have in common?

3. How are they different from the valence shells of He and Ar?

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NobelGasses

Ê HowareHe,NeandArdifferentfromalloftheotherelementsonthechartprovided?

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Use the periodic table above to answer the following. 1. What is the maximum number of electrons that each shell can hold?

1st Shell ___________ 2nd Shell __________ 3rd Shell ___________

Element Symbol # Protons # Neutrons #Electrons # Shells # Electrons in the valence shell

Carbon Hydrogen Oxygen Nitrogen Helium Argon

2. Compare the valence shell for C, H, O, and N. What do they have in common?

3. How are they different from the valence shells of He and Ar?

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TypesofBonds

Ê Wewilltalkabout4typesofbondsinthissection.______________________,_______________________________,____________________________and__________________________.Thefirstthreedealwithelectronsandthefourthtypeislikeamagnet,wheredifferentchargersareattractedtoeachother.

IonicBonds

Ê  Ionicbondsformbetweena_____________________anda_____________________________.Theelementwithalowionizationenergywill______________anegativelychargedelectronandbecomepositivewhiletheelementwiththehigherenergywill“take”thatelectronanbecomemore______________________.Ifyoulosetheelectronyouaresaidtobe“____________________________”,andifyougainanelectronyouaresaidtobe“_______________________________”,becauseyouarenowmorenegative.

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LEOsaysGER

Ê Rememberthat“LEOsaysGER”...Losingelectronsoxidation,gainingelectronsreduction.Nowthepositivelyandnegativelychargedionswillbe________________________attractedtooneanotherandformanionicbond.

TableSalt

Ê Thegoalistofilltheoutermostelectronshell.Insomecases,losingtheonlyelectroninyouroutershellmakesthenextshellclosesttothenucleusfull.WatchwhathappenswhenNaandClformNaClortablesaltyouhaveinyourkitchen

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D. Bonds in Chemistry

1. Ionic Bonds Ionic bonds usually occur between ________________ and _________________ in an effort to fill or empty the outer ______________ shells. One atom with low ionization energy will _______________ electrons from the valence shell and become a positively charged _________________. The loss of electrons is referred to as __________________. Remember that if you lose something negative, you become positive. The atom of another element, usually a______________________ will accept these electrons to complete the ___________________ shell. This atom will become negatively charged and referred to as an __________________. Gaining of electrons is referred to as ______________________. Remember that “LEO says GER”…Losing electrons oxidation, gaining electrons reduction. Now the positively and negatively charged ions will be ________________________ attracted to one another and form an ionic bond.

2. Covalent Bonds (strong) Covalent bonds involve the sharing of ______________ between atoms. The sharing of a single pair of electrons creates a single bond. Sharing of 2 pairs of electrons creates ___________________ bonds while sharing of 3 pairs of electrons creates ________________ bonds.

CovalentBonds

Ê Covalentbondsinvolvethesharingof______________betweenatoms.Thesharingofasinglepairofelectronscreatesasinglebond.Sharingof2pairsofelectronscreates___________________bondswhilesharingof3pairsofelectronscreates________________bonds.

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PolarvsNonPolarCovalentBonds

Ê Iftheelectronsaresharedequally,theyarecalled____________________________covalentbonds.IftheelectronsareNOTsharedequally,theyaresaidtobe__________________covalentbonds.Thiswillhappenifoneoftheatomsismore____________________________,whichmeansithasatendencytopulltheelectronstowardsitsnucleus,butnotpullthemoutoftheirvalenceshelllikeinanionicbond.

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Types of Covalent Bonds

(a)Non-polar Covalent Bonds: electrons are shared ____________________ between two or

more atoms. As a result, there is no net _______________________ charge. The absence of a

net charge does not allow these molecules to interact with water and they are referred to as

_______________________.

i.e.

(b) Polar Covalent Bonds: pairs of electrons shared ___________________ by 2 or more

atoms. Electrons will have a tendency to spend more time near the nucleus of the more

__________________________ atom thereby creating a _______________________ and

______________________ pole. This type of bond is what makes H20 so special.

__________________ has a stronger “attraction” for the ________________ than hydrogen

due to higher electronegativity. As a result, other polar molecules will be attracted to water

and they are referred to as ______________________.

Look at the image of the water molecule.

-Why does oxygen atom have a negative net charge while

the hydrogens have a positive charge?

i.e.

PolarCovalentBonds

Ê Inapolarcovalentbond,themoreelectronegativeatomwillhaveapartial–charge()leavingtheotheratomtohaveapartialpositivecharge().Thisisimportant,becausethisslightchargedifferencewillalladjacentmoleculestobeattractedtoeachotherforming____________________________bonds.Thesetypesofbondsarefoundholdingadjacentwatermoleculestoeachother.

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HydrogenBonds

Ê Becauseawatermoleculecontainspolarcovalentbonds,__________________________bondsformbetweenadjacentwatermolecules.Thisgiveswatermanyspecialanduniqueproperties.

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Properties of Water

A. Chemistry of Water Remember that water is a __________________ covalent molecule. When water molecules bond together, the positively charged _________________ is attracted to the negatively charged _________________ of the adjacent water molecule.

B. Special Properties of Water

1. _______________ is the ability of water molecules to stick together through _____________________ bonding. _________________________ is the name given to the cohesion of water molecules at the surface of a body of water.

2. _________________ is the ability of water molecules to stick to other surfaces. This is the result of hydrogen bonding with other molecules. Adhesion explains the formation of a __________________ and __________________ action.

3. Water is also considered the universal ____________________. Polar molecules are considered “water loving” or ______________________, and dissolve easily in water. Non-polar molecules are “water hating” or ____________________and do not dissolve in water.

4. Water is also less __________________ when frozen. When water freezes, a lattice forms due to the separation of hydrogen bonds. As a result, fresh water organisms can survive harsh winters.

5. The _____________________ ______________________ of water allows water to resist ______________________ change. This biologically important in regulating worldwide climate.

6. As liquid evaporates, the surface that remains will cool down. This is known as _________________ cooling. When organisms sweat, water molecules with ________________ kinetic energy will undergo a ___________________ change

Adhesion

Ê ____________________-istheabilityto“stick”to

otherpolarmaterials.

Thisishowawater

dropletcansticktoa

bladeofgrassforming

___________________.

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Adhesion

Ê  ___________________________istheabilityofwaterto“stick”tootherwatermolecules.Thisishowwatercanformdropletsofrainorforma“bubble”abovetherimofaglass.Thisallowswatertohaveapropertycalled_____________________________________.

SurfaceTension

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CapillaryAction

Ê Adhesionandcohesiontogetherallowwatertomove“upward”insmalltubes.Thisiscalled_______________________________________andoccursinthexylemofplants.Theprocessofwaterbeingdrawnfromtherootstotheleavesiscalled____________________________________.Aswatermoleculesevaporateorarelostbyaleaf,otherwatermoleculesgetpulledup

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EvaporativeCooling

Ê Aswaterevaporates,thehigherenergymoleculesarereleased,leavingthelowerenergymoleculesbehind.Thisisacoolingprocesscalled_______________________________________.Ourbodiescooldownasthesweatevaporatesfromourskin.Plantsalsostaycoolwhenwaterevaporatesfromtheirsurface

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SpecificHeat

Ê Waterhasahighspecificheat,whichmeansalotofenergyisneededtoraiseits________________________andalotofenergyneedstobelostinordertocoolitoff.Thispropertyallowstheclimateofcoastallocationtochangeveryslowlyandkeeptheplanetatarelativelyconstanttemperature.Locationssuchasthemoonhavetremendoustemperaturechangesbecauseofthelackofwaterbothonthesurfaceandintheatmosphere.Thedifferenceishundredsofdegrees.

Whyisthisabigdeal?

Ê  WhywilladesertregionlikeLasVegashavelargetemperaturechangesduringtheday,whilecoastallocationslikeLosAngelesareprettyconstant,eventhoughtheyareatthesamelatitude?

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IceandWater

Ê Wateris____________densewhenitfreezes.Thisoccursbecausethebondangleofwaterchangesattemperaturesbelow___________andformsadefinitelattice.Thisisimportantbecausetheicewillfloatandallowliquidwatertoremainliquidbelowtheicefororganismstosurviveduringthewinter.

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UniversalSolvent

Ê Waterisknownasthe_____________________________________becauseofitsnaturalabilitytodissolvemanysubstances.Ifasubstancemixeswithwatereasily,itisconsidered______________________________.Ifthematerialdoesnotmixwithwatereasily,itissaidtobe___________________________________.Fats,waxesandoilsareallhydrophobic.Thiswillbecomeveryimportantwhenwebegintalkingaboutthecell.

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IonizationofWater

Ê Waterwillionize,splitting2H2OmoleculesintoahydroniumionH3O+(H+)andahydroxideion(OH-.)Itshouldbeknownthattheconcentrationof[H+][OH-]=10-14

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Neutral

Ê Ifthe[H+][OH-]areinequalconcentrations,thepH=7andthesolutionissaidtobe_________________.Alittletrick,anysolutioncanhaveapHof7,notjustwater

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Let’sPractice

Ê  10-1=___________

Ê  10-7=___________

Ê  10-12=__________

Exponents

Ê  Ifyoumultiply2numberswithexponents,thenyouaddtheexponents,soif

Ê  [H+]=10-7and[OH-]=10-7,thentogethertheywillequal10-14

Ê  Thismeansthatthe[H+]concentrationis10-7sowesaythepHis7.

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AcidsandBases

Ê Thismakesallotherproblemssupereasy.RememberthatpHisthe[H+]concentration.pHrangesfrom1to14.AlowpH,lessthan7isconsidered________________whileahighpH,greaterthan7isconsidered_____________________.Although1seemslikealownumber,youhavetorememberthatitisreally10-1.Ifyouturnthatintoadecimal,thenthenumberis___________.Thatmeansthatthereisaveryhighconcentrationof[H+]ions,makingthesolutionacidic.

ReallyBasic

Ê IfthepHis13,thenitisbasicandthereisNOTahigh[H+]ionconcentrationbecause10-13reallyequals.0000000000001

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Let’sPractice

IfthepHis3isthisanacidorabase?IfthepHis9isthisanacidorabase?Whatisthe[H+]concentration? Whatisthe[H+]concentration?Whatisthe[OH-]concentration? Whatisthe[OH-]concentration?

IfthepHis12isthisanacidorabase?IfthepHis1isthisanacidorabase?Whatisthe[H+]concentration? Whatisthe[H+]concentration?Whatisthe[OH-]concentration? Whatisthe[OH-]concentration?

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IfthepHis5isthisanacidorabase?IfthepHis10isthisanacidorabase?Whatisthe[H+]concentration? Whatisthe[H+]concentration?Whatisthe[OH-]concentration? Whatisthe[OH-]concentration?