Chemical Bonds Physical Science. Valence Electrons Electrons found in the last shell, orbital or...
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Transcript of Chemical Bonds Physical Science. Valence Electrons Electrons found in the last shell, orbital or...
Chemical Bonds Chemical Bonds
Physical SciencePhysical Science
Valence Valence ElectronsElectrons
Electrons found in the Electrons found in the last shell, orbital or last shell, orbital or energy levelenergy level
Code :Code : 1,2,3,4,5,6,7,81,2,3,4,5,6,7,8
““A” columnsA” columns
Electron Dot DiagramsElectron Dot Diagrams
An An electron dot diagramelectron dot diagram is a model of an is a model of an atom in which each dot represents a atom in which each dot represents a valence electron. valence electron.
Stable configuration—eight valence Stable configuration—eight valence electronselectrons
Electron Dot PracticeElectron Dot Practice
1.1.He He _2_VE_2_VE
2.2.C C _4_VE_4_VE
3.3.Ca Ca _2_VE_2_VE
4.4.Na Na _1_VE_1_VE
5.5.Cl Cl _7_VE_7_VEVE= valence electrons
Valence Numbers/Oxidation NumbersValence Numbers/Oxidation NumbersNumber of electrons that the element will gain Number of electrons that the element will gain or lose to become stable.or lose to become stable.
Code:Code:+1,+2, +3, +/-4, -3, -2,-1,0+1,+2, +3, +/-4, -3, -2,-1,0
A columns onlyA columns only
IONSIONSCharged ParticlesCharged Particles
AnionAnion—an ion with a —an ion with a negative chargenegative charge
CationCation—an ion with a —an ion with a positive chargepositive charge
Goal of ALL ElementsGoal of ALL Elements
To have To have 88 electrons or the last electrons or the last shell full.shell full.
Which family is stable?Which family is stable?Nobel Gases (Inert Gases)Nobel Gases (Inert Gases)
Chemical BondingChemical Bonding
Chemical BondChemical Bond::– 2 or more elements 2 or more elements
chemically combine chemically combine to form a to form a compound.compound.
– The force holding The force holding atoms or ions atoms or ions togethertogether
Types of BondsTypes of Bonds
IonicIonic CovalentCovalent MetallicMetallic
Electrons are Electrons are gained or lost gained or lost
Electrons are Electrons are shared shared
Electrons are Electrons are gained or lostgained or lost
Metal and Metal and nonmetalnonmetal
EX: Table saltEX: Table salt
Nonmetal and Nonmetal and nonmetalnonmetal
EX: Water or EX: Water or sugarsugar
Metal and metalMetal and metal
EX: Any alloysEX: Any alloys
Properties and Arrangements in Properties and Arrangements in Ionic BondsIonic Bonds
PropertiesPropertiesIonization-Ionization- process of process of
elements losing elements losing electrons. (metals)electrons. (metals)
1A, 2A, 3A1A, 2A, 3A
Electron Affinity Electron Affinity – – process of elements process of elements gaining electrons. gaining electrons. (nonmetals)(nonmetals)
5A, 6A, 7A5A, 6A, 7A
Arrangement of IonsArrangement of Ions
Ratio shows equal Ratio shows equal proportionsproportions
Crystal shapeCrystal shape
Properties of Properties of Covalent BondsCovalent BondsShare electronsShare electrons
HH22 – Smallest covalent bond – Smallest covalent bond
knownknown
How do I write covalent How do I write covalent bonds?bonds?
H:H Electron Dot H:H Electron Dot ConfigurationConfiguration
Dots represent the electrons shared in Dots represent the electrons shared in
the bondthe bond
Diatomic AtomsDiatomic Atoms“Super Seven”“Super Seven”
DiDi means two. means two.
Definition: Definition: Elements combine Elements combine with itselfwith itself
Members of the Members of the “super seven”: “super seven”: Group 7A plus H, Group 7A plus H, N, and ON, and O
HH22
NN22
OO22
FF22
ClCl22
BrBr22
II22
Polyatomic IonsPolyatomic Ions
PolyPoly means many. means many.Definition: Compound acting as a Definition: Compound acting as a single charged element.single charged element.Examples:Examples: NHNH4 4 Ammonium Ammonium C C22HH33OO22 AcetateAcetate ClO ClO33 Chlorate OH Chlorate OH HydroxideHydroxide NO NO33 Nitrate Nitrate CO CO33 CarbonateCarbonate
SOSO44 Sulfate Sulfate PO PO44 PhosphatePhosphate
Element – Compounds - FormulasElement – Compounds - Formulas
ElementElementA particle A particle
that cannot that cannot be broken be broken down into down into
smaller smaller particlesparticles
CarbonCarbon
SymbolSymbol
Letters that Letters that represent represent
an elementan element
CC
CompoundCompound
Two or Two or more more
elements elements that that
chemically chemically combinecombine
Sodium Sodium chloridechloride
FormulasFormulas
Letters that Letters that represent a represent a compoundcompound
NaClNaCl
Bond ComparisonBond ComparisonBondsBonds Melting Melting
PointPointValence Valence
ElectronsElectronsElements Elements InvolvedInvolved
IonicIonic High High Melting PtMelting Pt
Gain or Gain or Lose Lose
ElectronsElectrons
Metals and Metals and NonmetalsNonmetals
CovalentCovalent Low Low Melting PtMelting Pt
Share Share ElectronsElectrons
Nonmetals Nonmetals and and
NonmetalsNonmetals
MetallicMetallic High High Melting PtMelting Pt
Free Free FlowingFlowing
ElectronsElectrons
Metals and Metals and MetalsMetals
Naming Compounds (Binary)Naming Compounds (Binary)Binary- 2 elementsBinary- 2 elements1.1.First First element is its element is its namename
2.2.SecondSecond element ends in element ends in –ide–ide
3.3.CombineCombine them together them together
NaClNaCl
Sodium ChlorSodium Chlorideide
Naming Compounds (Polyatomic)
Polyatomic- more than two elements.Polyatomic- more than two elements.1.1. First First element is its element is its namename
2.2. Name Name the the polyatomic ionpolyatomic ion
3. 3. CombineCombine together together
KNOKNO33
Potassium NitrPotassium Nitrateate
Key Thoughts for Naming
Never change the ending of a polyatomic
Change the ending of the single element only if it is the second element (-ide)
Practice in namingPractice in naming
KClKCl
MgOMgO
KClOKClO33
KCKC22HH33OO22
NHNH44NONO33
Potassium chlorPotassium chlorideide
Magnesium oxMagnesium oxideide
Potassium chlorPotassium chlorateate
Potassium acetPotassium acetateate
Ammonium nitrAmmonium nitrateate
Valence Numbers Valence Numbers Know the CodeKnow the Code
Valence NumbersValence Numbers are also known as are also known as OxidationOxidationnumbersnumbers
How many electrons an element will gain or lose to How many electrons an element will gain or lose to be stable.be stable.
Codes: Codes:
1A= +11A= +1 5A= –35A= –32A= +22A= +2 6A= –26A= –23A= +33A= +3 7A= –17A= –14A= +/- 44A= +/- 4 8A= 08A= 0
Writing and Balancing FormulasWriting and Balancing FormulasRulesRules
1.1. Write the Write the symbolssymbols
2.2. Write the Write the Valence #Valence # above each element.above each element.
3.3. See if the valence See if the valence number = number = 00. .
4.4. If not then cross over If not then cross over and write the oxidation and write the oxidation numbers as subscripts. numbers as subscripts. Don’t worry about the Don’t worry about the negative sign.negative sign.
Practice ProblemsPractice Problems
1.1. Mg ClMg Cl
2.2. K POK PO44
3.3. NHNH4 4 SOSO44
4.4. Sodium OxideSodium Oxide
AnswersAnswers
MgClMgCl22
KK33POPO44
(NH(NH44))22SOSO44
NaNa22OO
Formula and Naming with Weird Compounds
If using a transitional metal in naming, the charge of the metal is in parenthesis.
Covalent Bonds need to use prefixes– Ex: Carbon Dioxide = CO2