1. Bonding
atoms achieve a stable number of electrons (ionic and covalent)
involves valence (outer) electrons
make compounds and/or solids
fill out types of bonding chart using overhead
show overhead of metallic bonding
draw examples of ionic bonding – use skeletal models - MgO, NaCl, CaCl2, K2S
draw examples of covalent bonding – use skeletal models – CO2, H2O, O2

3. Metallic Bonding
All pure metals have metallic bonding and therefore exist as metallic structures.  Metallic bonding consists of a regular arrangement of positive ion cores of the metals surrounded by a mobile delocalized sea of electrons.

5. Metallic Bonding Each atom donates its valence electrons to the whole
Atom therefore becomes a cation (here called an ion core)
Donated electrons form an electron cloud surrounding all the ion cores
Electron cloud binds all the ion cores together by coulombic forces

6. Metallic Bonding Valence electrons are delocalized:
Shared by all atoms in the material
Electrons are free to drift throughout the material
Provides unique properties only found in metals
shiny metallic luster
good electrical and thermal conductivity
many others ...

7. Metallic Bonds: Mellow dogs with plenty of bones to go around
These bonds are best imagined as a room full of puppies who have plenty of bones to go around and are not possessive of any one particular bone.  This allows the electrons to move through the substance with little restriction.  The model is often described as the "kernels of atoms in a sea of electrons."

8. Ionic Bonding (ceramics and polymers)

9. Ionic bonding can be best imagined as one big greedy
Ionic Bonds: One big greedy thief dog!
Ionic bonding can be best imagined as one big greedy
dog stealing the other dog's bone.  If the bone
represents the electron that is up for grabs, then when
the big dog gains an electron he becomes negatively
charged and the little dog who lost the electron
becomes positively charged.  The two ions (that's where
the name ionic comes from) are attracted very strongly
to each other as a result of the opposite charges.

11. Sodium lets Chlorine use its valance electron

12. Covalent Bonding (Ceramics)

13. Covalent bonds can be thought of as two or more dogs
Covalent Bonds: Dogs of equal strength.
Covalent bonds can be thought of as two or more dogs
with equal attraction to the bones.  Since the dogs
(atoms) are identical, then the dogs share the pairs of
available bones evenly.  Since one dog does not have
more of the bone than the other dog, the charge is
evenly distributed among both dogs.  The molecule is not
"polar" meaning one side does not have more charge than
the other.

14. These bonds can be thought of as two or more dogs that
Polar Covalent Bonds: Unevenly matched but willing to share.
These bonds can be thought of as two or more dogs that
have different desire for bones.  The bigger dog has
more strength to possess a larger portion of the
bones.  Sharing still takes place but is an uneven
sharing.  In the case of the atoms, the electrons spend
more time on the end of the molecule near the atom
with the greater electronegativity (desire for the
electron) making it seem more negative and the other
end of the molecule seem more positive.

17. http://www. matsceng. ohio-state

19. Covalent Network Solid
only covalent bonds
extremely large molecules or networks
usually have at least one element from carbon family
very strong and hard
very high melt T°
some glass and ceramics, diamond
polymers are usually not because they make linear chains instead of networks

20. intermolecular forces high melt temps, nonconductors as solids,
Type of bonding
metallic
ionic
covalent
intermolecular forces
Type of elements used
Between metals
Metals and nonmetals
Between nonmetals
Between molecules
Givers &/or takers of electrons
Between givers
Between givers and takers
Between takers
Description
Valence e- roam freely between many atoms (delocalized). Sea of e- surrounding (+) kernels.
Transfer e-
Makes (+) and
(-) ions that are attracted to each other.
Share e-
Forms discrete molecules.
Hold covalently bonded molecules together as a solid.
Type of material formed
Solid metallic elements and alloys
Ceramics and glass
Polymers and some ceramics/glasses
Helps form solid polymers
Strength of bond
Relatively strong
Very strong
Weak
Properties
Produced
Good conductors, workable, corrode easily, generally high melt temps but variable
Brittle,
high melt temps, nonconductors as solids,
don’t corrode
Insulators,
Help determine a lot of properties of covalent compounds (polymers). Soft and plastic

21. Molecular formula

22. Molecular formula
Coefficient
Subscript

23. Identify number of atoms in the formula
Identify for the whole formula and for each element.
See NOTEBOOK for more detail.

24. Balancing equations

34. Electronic Configuration

35. Quantum Numbers
When describing orbitals and their components quantum mechanics uses 3 quantum numbers: n l ms

36. Quantum number n
Represents the energy level and its value (always a positive whole number).

37. Quantum number l
Identifies the energy sublevel and the shape of the orbital.
Value goes from 0 and n-1.

38. Quantum number ml Describes the space orientation of the orbitals.
Values go from -1 to +1, including 0.

39. Quantum number ms
Describes the spin of the electron in an orbital.

41. Energy levels
Energy Level
Number of Electrons 1 2 8 3 18 4 32 5 6 7

42. Energy sublevels
Energy Level
Energy Sublevel 1 2 3 4 5 6 7

43. Electron Orbitals
Orbital
Number of Electrons s 2 p 6 d 10 f 14

45. Electronic Configuration
Distribution and organization of the electrons throughout the orbitals of an atom.
When completing the electronic configuration of an atom we have to consider three rules.
Aufbau Principal
Pauli's Exclusion Principal
Hund's Rule

46. Aufbau Principal
According to this rule, electrons occupy the orbitals of lowest energy first.
The orbitals of any sublevel are of equal energy.

47. Pauli’s Exclusion Principal
This rule establishes that an orbital can have at most 2 electrons, but these electrons have to have opposite spins.
e- #1 – arrow looking up (clockwise spin)
e- #2 – arrow looking down (counterclockwise spin)

48. Hund’s Rule
This rule states that electrons that are on the same energy sublevel, need to fill all the orbitals with the same spin and then complete with the opposite electron.

50. Examples

51. Practice!!!

52. Coming topics: Nomenclature and Lewis Structure