1. Bonding in Atoms
What keeps us together

2. Valence Electrons Electrons located in the outer shell
Readily available for bonding
Always s or p sublevel
Follows the Octet Rule
Modeled by the Lewis Dot Diagram

3. The Octet Rule
States that an atom will lose or gain electrons in order to fill the outer sublevels (s and p)
Modeled by the Lewis Dot Diagram
Gain of electrons = anion
Loss of electrons = cations

4. Common Anions ( -1) F- Fluoride NO- Nitrate I- Iodide C2H3O2- Acetate
OH-
Hydroxide
MnO4-
Permanganate
Cl-
Chloride
CN-
Cyanide
ClO-
Hypochlorite
Br-
Bromide
ClO2-
Chlorite
BrO3-
Bromate
ClO3-
Chlorate
HCO3-
Hydrogen Carbonate

5. Common Anions (-2) O-2 Oxide S-2 Sulfide SO4-2 Sulfate CO3-2 Carbonate
Cr2O7-2
Dichromate
CrO4-2
Chromate

6. Common Anions (-3)
N-3
Nitride
P-3
Phosphide
PO4-3
Phosphate

7. Chemical Formulas and Units
A chemical formula shows the kinds of atoms in the molecule as well as the amount of atoms in the molecule
A formula unit is expressed in the smallest whole number ratio for the molecule
Examples:
NaCl
TiO2
VCl5
Ca3(PO4)2

8. Ionic Bonding
The single most important thing about ionic bonds = ELECTRONS ARE EXCHANGED
Ionic bonds occur between a METAL and a NONMETAL (Cation and Anion)
High Boiling Point
High Melting Point
Good Insulator (Solid)
Good conductor
Liquid (Melted) or Aqueous
Aqueous = Dissolved

9. Ionic Bond Characteristics Explained
Compounds of ionic bonding are often solid at room temperature
Ionic compounds will have a lattice structure or a 3D crystalline shape
The structure is responsible for:
High melting points
High boiling points
Insulating Solid (electrons are stored)
Conductive liquids and solutions (electrons are free)

10. Binary Ionic Compounds
A Bicycle has how many wheels?
A biplane has how many wings?
A binary compound has how many elements?
A binary ionic compound has two elements where electrons are exchanged
NaCl
MgBr2
Ca3N2
Sodium Chloride
Magnesium Bromide
Calcium Nitride

11. Polyatomic Ions What is polytheism? What is a polygon?
How about polyatomic ions?
Polyatomic ions are IONS that consist of multiple atoms
Polyatomic ions are used in ionic bonding because there is still an exchange in electrons

12. Covalent Bonding
The single most important thing about covalent bonds: ELECTRONS ARE SHARED
Covalent Bonds occur between a NONMETAL and a NONMETAL
Low Melting Point
Low Boiling Point
Poor Conductivity
Polar Nature
Usually liquids and gases at S.T.P.
Standard Temperature and Pressure

13. Covalent Bonding Explained
Bonds can occur as single, double, or triple bonds
Each bond represents a PAIR (2) of electrons
Best represented in diatomic molecules (F, Cl, Br, I, H, N, O)
Lewis Dot Diagram helps determine where a double or triple bond can occur
Polarity is a result of unequal distribution of electrons ∴ the bond creates a positive end (pole) and a negative end (pole)
Covalent Bonds are the root of Organic Chemistry

14. Covalent Bonding VSEPR Theory
Valance shell electron pair repulsion theory
Predicts the shape of a molecule (covalent compound)
Lone pair on the central atom push the ligands together altering the bond angles between the ligands
Practice: CHI3, CO2, NH3, CH2O, SO3, HCN

15. VSEPR Shapes

16. Covalent Naming
Name is determined by the number of atoms in the molecule
MUST be covalent
CO2, SO3, O3, C3O6

17. May the Force Be with You
London Dispersion / Van Der Waals Forces
Weakest – electrons of one compound attracted to the nucleus of another
Includes compounds with non-polar forces
Increases as the number of electrons increases
Dipole-Dipole Forces
Next strongest
Between compounds that are polar
Increases as mass increases
Hydrogen bonding (The super dipole force)
Attraction between molecules:
H-F, H-N, H-O

18. Properties of Intermolecular Forces
Viscosity – the measure of a fluids ability to flow
Greater forces = greater resistance to flow
Inverse relationship with temperature
Surface Tension – energy required to increase the surface area of a liquid
Increases with stronger dipole-dipole
Water is an excellent example
Capillary Action – ability of a liquid
to flow against gravity
Cohesion – Attraction within liquid
Adhesion – Attraction to container

19. Transition Metals
Transition metals have empty orbitals available for electron movement
This movement results in multiple cations
Cations can be predicted using electron notation
Let’s look at copper!

20. Transition Metal Cations

21. Metallic Bonding Occurs between METAL and METAL
Electron ”sea” develops when metals lose their electrons
This “sea” gives the metals unique properties because the electrons are free to move at will
The ”sea” is strong, but easily influenced by other atoms with high electronegativity

22. Characteristics of Metallic Bonds
High Melting Point – Sea and heavy atoms
High Boiling Point– Sea and heavy atoms
High Conductivity – Electrons are free to flow
Malleability – Ability to pound into sheets due to free moving electrons, no bonds
Ductility – Ability to stretch into a wire due to free moving electrons, no bonds
Luster – shiny appearance, free electrons are reflecting the light

23. Determining the Bond Use the electronegativity trend
If they are close = covalent
If they are far = ionic
If they are both metals = metallic
If there are multiple atoms that are close and far = covalent and ionic

24. Ionic Covalent Metallic NaCl NaNO3 CO4 Ag2CrO4 K2O N2O2 Fe2O3 TiC PCl5
What would the bond be?
NaCl
NaNO3
CO4
Ag2CrO4
K2O
N2O2
Fe2O3
TiC
PCl5
CuZn
Ionic
Covalent
Metallic