1. In the time that it takes the music to play…write as much as you know about bonds… Compound with the most correct wins!

2. What determines the type of bond that forms?

3. ELECTRONEGATIVITY The tendency of an atom to attract electrons to itself when it is bonded to another atom

4. BOND STRENGTH the energy needed to break the bonds between atoms in a compound

5. Bond Strength
The greater the difference in electronegativities, the greater the bond strength

6. Misconception Alert!
It does not require energy to make bonds. It requires energy to break bonds. “Breaking up is hard to do”

7. 2 Main Bonding Options By transferring electrons (producing ions)
(big difference in EN)
By sharing electrons
(small difference in EN)

8. IONIC BOND bond formed between two ions by the transfer of electrons (difference in EN > 1.67)

9. IONIC COMPOUND substance formed when electrons are transferred between 2 or more substances (making ions)

10. Example of an Ionic Bond
Chlorine steals one of sodium’s electrons

11. Characteristics of Ionic Substances
Electrons are transferred
Bonds between metals and non-metals
Formulas are in simple ratios (NaCl)

12. More Characteristics of Ionic Substances
Crystalline structure at room temperature
High melting points
Good conductors of electricity when molten or dissolved

13. COVALENT BOND bond formed by the sharing of electrons (difference in EN < 1.67)

14. MOLECULE a neutral group of atoms held together by covalent bonds (ex: H2O)

15. Example of a Covalent Bond
Each of Hydrogen’s electrons are shared to make H2

16. Characteristics of Covalent Substances
Electrons are shared
Bonds between non-metals and other non-metals
Formulas are in true ratio of atoms (C6H12O6)

17. More Characteristics of Ionic Substances
Substances may exist in any state of matter at room temperature
Low melting points
Nonconductors of electricity

18. Bonds in all the polyatomic ions and diatomics are all covalent bonds

19. The ability to conduct an electrical current
CONDUCTIVITY
The ability to conduct an electrical current

20. Can we use conductivity to determine if a substance is ionic or covalent?

21. Ionic bonds are stronger than covalent
WHICH IS STRONGER?
Ionic bonds are stronger than covalent

22. when electrons are shared but shared unequally
POLAR COVALENT BONDS
when electrons are shared but shared unequally
H2O

23. Example of a Polar Covalent Bond
                                                  A dipole caused by the polar covalent bond of the water molecule.
An unequal sharing of hydrogen’s electrons

24. Unequal sharing creates areas of positive and negative charge on a polar compound.

25. O • H x d+
d-2
Dipole Moment

26. Structure of Soap

27. The slight differences in charge bond water molecules together (H-Bonding)

28. HOMEWORK Do problems 3-4 on page 306 of the text. Pg. 304 #1,2

29. CH4 H H C H H Covalent Lewis Structure: Methane Write Formula:
MAKE THE SKELETON! H H C H H

30. CH4 (1)(4) = 4 C = (4)(1) = 4 H = 8 valence e-s
Covalent Lewis Structure: Methane
CH4
Write Formula:
1) Calculate # of Valence e-:
Element = (# of Atoms)(# of Valence e-s)
(1)(4) = 4
C =
H =
(4)(1) = 4
8 valence e-s
2) Not an ion

31. CH4 H H C H H 8 v. e-s -8=0 Covalent Lewis Structure: Methane
3) Place Bonding Pairs
4) Complete Ligand Octets H
5) Add left overs H C H
6) Check for stability
Central Octet? H
b. <8 (B?) Multiple Bonds
c. >8, OK for Periods 3-7

32. CH4 H H C H H Covalent Lewis Structure: Methane
7) Draw the Lewis LINE Structure H H C H H

33. BF3 F F B F Covalent Lewis Structure: Boron Trifluoride Write Formula:
MAKE THE SKELETON! F F B F

34. BF3 (1)(3) = 3 B = (3)(7) = 21 F = 24 valence e-s
Covalent Lewis Structure: Boron Trifluoride
BF3
Write Formula:
1) Calculate # of Valence e-:
Element = (# of Atoms)(# of Valence e-s)
(1)(3) = 3
B =
F =
(3)(7) = 21
24 valence e-s
2) Not an ion

35. BF3 F F B F 24 v. e-s Covalent Lewis Structure: Boron Trifluoride
-6=18
-18=0
3) Place Bonding Pairs
4) Complete Ligand Octets F
5) Add left overs F B F
6) Check for stability
Central Octet?
b. <8 (B?) Multiple Bonds
c. >8, OK for Periods 3-7

36. Carbon makes LOTS of bonds…but never more than 4
CARBON BONDS
Carbon makes LOTS of bonds…but never more than 4

38. Tartrate

40. Trigonal Planar
Bent

41. Tetrahedral

42. Tetrahedral Bent (2 lone pairs)
Trigonal Pyramidal
Bent (2 lone pairs)

43. IONIC COMPOUND substance formed when electrons are transferred between 2 or more substances (making ions)

44. How do you name ionic compounds?

45. How do you write ionic compounds?

46. Kris Kross Method!
Ca2+As3-
Ca3As2

47. Just kris kross the positive and the negative charges
Na1+Cl1-
NaCl
Pb4+O2-
Pb2O4

48. Which charge ALWAYS comes first?
POSITIVE!!!

49. Are you sure?

50. For Polyatomics it gets a bit more complex
Pb4+SO43-
Pb3(SO4)4
NH4 1+PO43-
(NH4)3 PO4