1. Chapter 6 Chemical Bonding
Why do elements combine?
atoms like to have full valence shells.

3. 3 Types of Bonds
1. Ionic
2. Covalent
3. Metallic

4. Electronegativity and bonding
Ionic Bonding
If the difference in electronegativity is more than 1.7 then the bond is ionic.
Covalent Bonding
1. Polar
If the difference in electronegativity is
then the bond is considered Polar Covalent
2. Nonpolar
If the difference in electronegativity is 0-.3 then the bond is non-polar covalent

5. IONIC BONDS Results from the attraction between (+) and (-) ions.
Metal and Non-Metal
Metals lose –e to form a positive ion
They will lose enough to get to the full shell underneath.
Non-metals gain –e forming a negative ion.
They will gain enough to get to a full outer shell.
The electrons involved are the valence electrons
(+) & (-) ions are attracted to each other so that the charges balance
Formula Unit-A formula that shows the least amount of each ion you must have in order for the charges to balance

6. Physical Properties of Ionic Compounds
Most are solids in the form of salts
Crystalline Lattice
Hard but Brittle
Conduct electricity in the molten state or in a solution.
Soluble in water
Very strong bond
High melting points

7. Hydrogen Carbonate (Bicarbonate)
Polyatomic Ions
A charged group of covalently bonded atoms
Write the Formula Unit for an ionic compound with
K and SO4-2
Al and NO2-1
Na and OH-1
Ca and PO43-
Note that the whole “group” of atoms has a charge.
Ammonium
NH4+
Chlorate
ClO32-
Hydrogen Carbonate (Bicarbonate)
HCO3-
Chromate
CrO42-
Hydroxide
OH-
Sulfate
SO42-
Nitrate
NO3-
Sulfite
SO32-
Nitrite
NO2-
Phosphate
PO43-
Perchlorate
ClO4-
Carbonate
CO32-

8. Practice
Formation of ionic compounds c/groups_interactive.html

9. Covalent Bonds Between Non-Metal and Non-Metal
Valence Electrons are shared between atoms
Covalent Compounds are Represented by a molecular formula-Shows all the elements in the compound
H2O
C2H6O4
Lower melting and boiling points than ionic compounds

10. How are bonds represented?
Electron Dot Notation is used to make Lewis Structures
Lewis Structures
A pair of electrons is represented by a dash ………….
H Cl > H-Cl
Pairs of electrons that are not bonded are called an unshared pair of electrons.

11. Tips for Drawing Lewis Structures
Hydrogen and the halogens will never be a central atom. Why?
They can only form one bond
If the compound contains carbon then it will be in the middle. If no carbon then the least electronegative element will be in the middle. Why?
Because these elements can form more than one covalent bond.
The overall goal is to make each central atom have an octet of electrons
a)CH4 b)C2H6 c)NH3 d)SiF4

12. Multiple Covalent Bonds
If you cannot satisfy the octet rule with a single bond, try a double or triple bond.
Double (two atoms share two pairs of electrons)
Triple (two atoms share three pairs of electrons)
Usually involve carbon, nitrogen, and oxygen.

13. Polar Covalent Bonds Occurs between two different nonmetal elements
Examples:
carbon and oxygen
hydrogen and oxygen
hydrogen and chlorine

14. Polar Covalent bonds continued
Polar bonds result due to an unequal sharing of the electron pair.
A pole is created due to one of the bonded atoms having a higher electronegativity.
Also when there are unshared pairs of electrons
Let’s draw the pole that is created by
the following pairs of atoms
carbon and oxygen
hydrogen and oxygen
hydrogen and chlorine
HCl

15. Non Polar Covalent Bonds
Result from an equal sharing of the electron pair.
Mostly occur between like atoms

16. Non Polar Covalent Bonds
Diatomic Molecules are molecules that contain the same element
Seven common diatomic molecules
Iodine I2
Hydrogen H2
Chlorine Cl2
Fluorine F2
Nitrogen N2
Bromine Br2
Oxygen O2

17. Non-Polar Covalent Cont
A bond is also called non polar if the molecule is symmetrical.
H : C ::: C : H

18. Intermolecular Forces or Vander waAls Forces
Forces or attractions between molecules
Much Weaker than bonds that join atoms (so much weaker than covalent bonds or ionic bonds)

19. 1. London Dispersion Forces
Occurs in all atoms and molecules
Due to the constant motion of electrons
Increase with increasing mass of atoms
Helium Gas

20. 2. Dipole-Dipole Acts between polar molecules
H-bonds are represented by dotted lines or dashes
Partial Charges of polar molecules attract one another

21. 3. Hydrogen Bonding A type of Dipole-Dipole Force
Strongest of intermolecular forces
Occurs between a hydrogen that is covalently bonded to a F, O,or N and an unshared pair of electrons on another molecule.

22. http://www.onlinemathlearning.com/interm olecular-forces.html

23. Are there different types? If so what are the types?
Properties
Covalent Bonds
Ionic Bonds
How does it form? Hint: what happens with the electrons?
Are there different types? If so what are the types?
Does it have a definite Shape?
Melting point? High or low
What is it?Define it.
Boiling point? High or Low
Examples:
Occurs between what type of atoms?
State at room temperature?

24. How does it form? Hint: what happens with the electrons?
Properties
Covalent Bonds
Ionic Bonds
How does it form? Hint: what happens with the electrons?
A covalent bond is formed between two non-metals that have similar electronegativities. Neither atom is "strong" enough to attract electrons from the other. To help each out, they share their Valence electrons
An ionic bond is formed between a metal and a non-metal. Non-metals take electrons from the metals. Non-metals form a negative ion and Metals form a positive ion. These two opposite ions attract each other and form the ionic bond.
Are there different types?
If so what are the types?
Yes, Polar covalent and non-polar covalent
No different types
Does it have a definite Shape?
Definite shape bonds cannot shift
Crystalline Lattice Structure-can shift and reform bonds
Melting point? High or low
low
High
What is it?
Define it.
Covalent bonding is a form of chemical bonding between two non metal atoms. They share pairs of electrons.
Ionic bond is a type of bond formed from the attraction between oppositely charged ions in a chemical compound. These kinds of bonds occur between a metal and a non metal atom.
Boiling point? High or Low
Low
Examples:
Methane (CH4), HydroChloric acid (HCl), Water (H2O)
Sodium chloride-Table Salt (NaCl)
Occurs between what type of atoms?
Two non-metals
One metal and one non-metal
State at room temperature?
Gaseous, Liquid, or brittle solid
Solid

25. Metallic bonding
bond.html

26. Vocabulary for Ionic bonding
Anion
Cation
Ionic Compound
Lattice Structure
Polyatomic Ion
Valence Electron
Formula Unit
Intramolecular Force

27. V: Valence S: Shell E: Electron P: Pair R: Repulsion VsepR Models
VSEPR Models: a model used to predict the shape of individual molecules based on the fact that electron pairs want to get as far away from other electrons pairs as possible.
V: Valence
S: Shell
E: Electron
P: Pair
R: Repulsion

28. Baby Research Paper: What is Orbital Hybridization?
Combine the concepts of hybrid orbitals and VSEPR Models to describe the shapes and structures of some common molecules.
Draw Pictures and give examples
Be sure to include information about sp, sp2, and sp3
2 pages (no more than ½ page should be taken up with pictures)
1 in Margins
12 in font (Times New Roman)
Cover Page w/ Title, Name, Block, Date
Due Monday 21st