1. Atomic Theory Practice
Name the element:
Na2311
?3216
?146
?3919+
Group IIA, Period 3
1s22s22p5
Sodium
Sulfur
Carbon-14
Potassium ion
Magnesium
Fluorine

2. Bonding, Shape, Polarity & Reactions
MOLECULAR MADNESS
Bonding, Shape, Polarity &
Reactions

3. ATOMIC THEORY Atoms composed of subatomic particles Protons Neutrons
Electrons + -
Nucleus
Orbitals
Atomic #
Atomic mass – atomic #
Unchangeable
Isotopes
Ions
Cation +
Less e-
Anion –
More e-

4. Exothermic (heat emitting, i.e. chem warm up :) Exercise #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)
Ionic – transfer electrons
Covalent – share electrons

5. BONDING Ionic Bonds Transferred electrons
Formed between metals & nonmetals
Metals = + cations w/full valence
Nonmetals = - anions w/full valence
Opposing charges attract STRONGLY
Ionic Compounds
High melting pts
Good electrical conductors in solution

6. Ionic Bonding - Lewis Dot structures

7. BONDING Covalent Bonds – shared electrons Non-polar Covalent
e- shared equally
atoms w/similar electronegativities
Polar Covalent
e- shared Unequally
atoms w/different electronegativities

8. Covalent Bonding - Lewis Dot structures
Polar or
Nonpolar?
Nonpolar
Polar or
Nonpolar?
Nonpolar
Polar or
Nonpolar?
Polar

9. Polarity in Molecules Nonpolar Molecules Polar Molecules
Very little attraction between them
Generally room temp
Ex: CO2
Polar Molecules
Have dipoles (ends with opposite charges)
Electrons pulled toward more electronegative atom
Attraction between dipoles of adjacent molecules
Ex: H2O
CO2

10. VSEPR Theory Valence Shell Electron Pair Repulsion Sample Shapes
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
chemistry.gcsu.edu
Bent

11. Bond Length Periodic Trend
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

12. Intermolecular Forces
Hydrogen Bonds
Formed between molecules whose atoms have extremely different electronegativities
Most electronegative atoms: F, O, N
bonded to
Least electronegative atom: H
Strong intermolecular force, causing high boiling points
Not nearly as strong as INTRAmolecular bonds like covalent

13. Bonding Review

14. Endergonic (chem energy INTO your brain :) Exercise #1
In textbook,
Read p.275
Answer the following questions from p :
MC 1,2,6,10
T/F 13,18
CM 22,24,26

15. Chemical Reactions Reactants – What goes in Products – What comes out
Substances converted into NEW substances w/NEW properties
Reactants – What goes in
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)
Words
Formulas
Balanced Equation
Complete Equation

16. Writing & Balancing Chemical Equations
Going from word formula to balanced…
Remember your naming rules!
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
Covalent compounds – use the number prefixes to indicate numbers of atoms
Carbon + Chlorine  Carbon Tetrachloride
C + 2Cl2  CCl4

17. Ions & Charges Cations +1 Group 1 atoms Ammonium NH4+1 +2
Anions -1
Group 7 atoms
Chlorate = ClO3-1
Nitrate = NO3-1
Hydroxide = OH-1 -2
Group 6 atoms
Sulfate = SO4-2
Carbonate = CO3-2 -3
Group 5 atoms
Phosphate = PO4-3

18. Naming & Writing Gases & Acids
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
Acids
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

19. Types of Chemical Reactions
Synthesis Reaction
aka direct combination reaction
2 or more reactants come together to form a single product
A + B  AB
2Na + Cl2  2NaCl
Decomposition Reaction
Single compound broken down into 2 or more smaller products
AB  A + B
2H2O  2H2 + O2

20. Types of Chemical Reactions
Single 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

21. Types of Chemical Reactions
Double Replacement Reaction
Atoms or ions from 2 different compounds replace each other
AX + BY  AY + BX
CaCO3 + 2HCl  CaCl2 + H2CO3