Atomic Theory PracticeAtomic Theory Practice
Name the element:
1. Na2311
2. ?3216
3. ?146
4. ?3919
+
5. Group IIA, Period 3
6. 1s22s22p5
SodiumSodium
SulfurSulfur
Carbon-14Carbon-14
Potassium ionPotassium ion
MagnesiumMagnesium
FluorineFluorine
MOLECULAR MOLECULAR MADNESSMADNESSBonding, Shape, Polarity & Bonding, Shape, Polarity &
ReactionsReactions
ATOMIC THEORYATOMIC THEORY
ProtonsProtons NeutronsNeutrons ElectronsElectrons
+ 0 -
Nucleus Nucleus Orbitals
Atomic # Atomic mass – atomic #
Atomic #
Unchangeable IsotopesIsotopes IonsIons• CationCation +
•Less e-• AnionAnion –
•More e-
• Atoms composed of subatomic particles
Exothermic Exothermic (heat emitting, i.e. chem warm up :) (heat emitting, i.e. chem warm up :)
Exercise #1Exercise #1
A. Draw the Lewis structure for Carbon.
B. Why do atoms bond with one another?
C. What are the 2 main types of intramolecular bonds?
To fill their valence shell (Octet Rule)
1.1. IonicIonic – transfer electrons2.2. CovalentCovalent – share electrons
BONDINGBONDINGIonic BondsIonic Bonds • Transferred electrons• Formed between metals & nonmetals
• Metals = + cations w/full valence• Nonmetals = - anions w/full valence
• Opposing charges attract STRONGLY
Ionic CompoundsIonic Compounds • High melting pts• Good electrical conductors in solution
Ionic Bonding - Lewis Dot structuresIonic Bonding - Lewis Dot structures
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html
BONDINGBONDING
Non-polar CovalentNon-polar Covalent• e- shared equally• atoms w/similar
electronegativities
Polar CovalentPolar Covalent• e- shared UnUnequally• atoms w/different
electronegativities
Covalent BondsCovalent Bonds – shared electrons
http://iws.collin.edu/biopage/faculty/mcculloch/1406/outlines/chapter%202/chap02.html
Covalent Bonding Covalent Bonding - Lewis Dot structures- Lewis Dot structures
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html
Polar or Polar or Nonpolar?Nonpolar?
Polar or Polar or Nonpolar?Nonpolar?
Polar or Polar or Nonpolar?Nonpolar?
NonpolarNonpolar
NonpolarNonpolar
PolarPolar
Polarity in MoleculesPolarity in MoleculesNonpolarNonpolar Molecules
• Very little attraction between them• Generally gases @ room temp
• Ex: CO2
PolarPolar Molecules• Have dipoles (ends with opposite charges)• Electrons pulled toward more electronegative atom• Attraction between dipoles of adjacent molecules
• Ex: H2O
http://www.chem.umass.edu/genchem/whelan/class_images/Structure_of_Water.jpghttp://www.chem1.com/acad/webtext/states/interact.html
CO2
http://www.exo.net/~pauld/workshops/Greenhouse%20Effect/greenhouse.html
VSEPR TheoryVSEPR Theory• VValence SShell
EElectron PPair RRepulsion• Outer shell e- pair up• Arrange themselves
as far apart from other pairs as possible since they repel other neg. charges
• Responsible for molecular shape
Sample Shapes
Bent
chemistry.gcsu.edu
Bond LengthBond Length
Periodic Trend• as you move down group and right to left within a
period, bond length increases
• Same as atomic radius
• Double & triple bonds
are shorter than single
Radius & bond length increase
http://chemwiki.ucdavis.edu/Theoretical_Chemistry/Chemical_Bonding/Bond_Order_and_Lengths
http://www.chem.latech.edu/~upali/chem101/101MSJc8.htm
Intermolecular ForcesIntermolecular Forces
Hydrogen Bonds• Formed between molecules whose atoms have
extremely different electronegativities• Most electronegative atoms: F, O, NF, O, N
bonded to• Least electronegative atom: HH
• Strong intermolecular force, causing high boiling points• Not nearly as strong as INTRAmolecular bonds
like covalent
Bonding ReviewBonding Review
Endergonic Endergonic (chem energy INTO your brain :)
Exercise #1Exercise #1
• In textbook, • Read p.275• Answer the following questions from p.276-77:
• MC 1,2,6,10• T/F 13,18• CM 22,24,26
Chemical ReactionsChemical Reactions• Substances converted into NEW substances w/NEW
properties
Reactants – Reactants – What goes in
Products – Products – What comes out
Reactants Products
Glucose + Oxygen Carbon Dioxide + Water
C6H12O6 + O2 CO2 + H2O
C6H12O6 + 6O2 6CO2 + 6H2O
C6H12O6(s) + O2(g) CO2(g) + H2O(l)
WordsWords
FormulasFormulas
Balanced EquationBalanced Equation
Complete EquationComplete Equation
Writing & Balancing Chemical Writing & Balancing Chemical EquationsEquations
• Going from word formula to balanced…1. Remember your naming rules!
a. Ionic compounds – cation (+) first then anion (-)
• # of + charges must equal # of - charges
• Ex: Sodium + Chlorine Sodium Chloride
Na+ + Cl- NaCl• Ex: Aluminum nitrate + Iron chloride Iron Nitrate + Aluminum Chloride
Al(NO3)3 + FeCl2 Fe(NO3)2 + AlCl3
a. Covalent compounds – use the number prefixes to indicate numbers of atoms
• Carbon + Chlorine Carbon Tetrachloride
C + 2Cl2 CCl4
Ions & ChargesIons & ChargesCationsCations
+1+1• Group 1 atoms • Ammonium
• NH4+1
+2+2• Group 2 atoms
AnionsAnions-1-1
• Group 7 atoms • Chlorate = ClOChlorate = ClO33
-1-1
• Nitrate = NONitrate = NO33-1-1
• Hydroxide = OHHydroxide = OH-1-1
-2-2• Group 6 atoms• Sulfate = SOSulfate = SO44--22
• Carbonate = COCarbonate = CO33-2-2
-3-3• Group 5 atoms• Phosphate = POPhosphate = PO44
-3-3
Naming & Writing Gases & AcidsNaming & Writing Gases & Acids
GasesGases• The name of the element followed by the word gas is always a
diatomic molecule• Ex: Oxygen gas = O2
• Ex: Chlorine gas = Cl2
• Ex: Hydrogen gas = H2
AcidsAcids• The name of an ion followed by the word acid means you add
the appropriate # of H’s in front of the ion• The # of H’s equals the - charge of the anion
• Ex: Hydrochloric acid = HCl• Ex: Sulfuric acid = H2SO4
• Ex: Phosphoric acid = H3PO4
Types of Chemical ReactionsTypes of Chemical Reactions
1.1. Synthesis ReactionSynthesis Reaction
• aka direct combination reaction
• 2 or more reactants come together to form a single product
• A + B AB
• 2Na + Cl2 2NaCl
2.2. Decomposition ReactionDecomposition Reaction
• Single compound broken down into 2 or more smaller products
• AB A + B
• 2H2O 2H2 + O2
3.3. Single Replacement ReactionSingle Replacement Reaction• Uncombined element takes the place of another
element within a compound• A + BX AX + B
• Mg + CuSO4 MgSO4 + Cu
• More active elements replace less active ones• Activity level shown in activity series• If uncombined element NOT more active, then
no reaction takes place
Types of Chemical ReactionsTypes of Chemical Reactions
4. Double Replacement Reaction• Atoms or ions from 2 different compounds
replace each other• AX + BY AY + BX
• CaCO3 + 2HCl CaCl2 + H2CO3
Types of Chemical ReactionsTypes of Chemical Reactions