1. CHEMICAL BONDING
IONIC BONDS
COVALENT BONDS
HYDROGEN BONDS
METALLIC BONDS

2. IONIC BONDING

3. IONIC BONDING When an atom of a nonmetal takes one or more electrons
from an atom of a metal
so both atoms end up with
eight valence electrons

4. IONIC BONDING IS THE COMPOUND AN IONIC COMPOUND? Mg N 3 2 NONMETAL
SUBSCRIPTS

5. IONIC BOND FORMATION Non-Metal Metal
Neutral atoms come near each other. Electron(s) are transferred from the Metal atom to the Non-metal atom. They stick together because of electrostatic forces, like magnets.

6. Metals will tend to lose electrons and become
IONIC BONDING
Metals will tend to lose electrons and become
POSITIVE CATIONS = Na
11 p
10 e + -
to become sodium ion + -
11 p
11 e Na
Normal sodium atom - 1e
loses one electron

7. Nonmetals will tend to gain electrons and become
IONIC BONDING
Nonmetals will tend to gain electrons and become
NEGATIVE ANIONS
17 p
17 e + - Cl
Normal chlorine atom = Cl
17 p
18 e + -
to become a chloride ion + 1e -
gains an electron

8. NH4+1--ammonium ion CO3-2--carbonate ion PO4-3--phosphate ion
IONIC BONDING
POLYATOMIC IONS--a group of atoms that act like one ion
NH4+1--ammonium ion
CO3-2--carbonate ion
PO4-3--phosphate ion

9. IONIC BONDING
Na SO 2 4
SODIUM SULFATE

10. Properties of Ionic Compounds
Crystalline structure.
A regular repeating arrangement of ions in the solid.
Ions are strongly bonded.
Structure is rigid.
High melting points- because of strong forces between ions.

11. Crystalline structure
The POSITIVE CATIONS stick to the NEGATIVE ANIONS, like a magnet. + + - - - - + + - + - + + - - - + +

12. Do they Conduct? Conducting electricity is allowing charges to move.
In a solid, the ions are locked in place.
Ionic solids are insulators.
When melted, the ions can move around.
Melted ionic compounds conduct.
First get them to 800ºC.
Dissolved in water they conduct.

13. Ionic solids are brittle+ -

14. Ionic solids are brittle
Strong Repulsion breaks crystal apart. + - + - + - + -

15. COVALENT BONDING

16. When an atom of one nonmetal shares one or more electrons
COVALENT BONDING
When an atom of one nonmetal
shares one or more electrons
with an atom of another
nonmetal so both atoms
end up with
eight valence electrons

17. COVALENT BOND FORMATION
When one nonmetal shares one or more electrons with an atom of another nonmetal so both atoms end up with eight valence electrons

18. COVALENT BONDING IS THE COMPOUND A COVALENT COMPOUND? C O 2 NONMETAL
YES since it is made of only nonmetal elements

19. Covalent bonding
Fluorine has seven valence electrons F

20. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven F F

21. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven
By sharing electrons F F

22. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven
By sharing electrons F F

23. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven
By sharing electrons F F

24. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven
By sharing electrons F F

25. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven
By sharing electrons F F

26. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven
By sharing electrons
Both end with full orbitals F F

27. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven
By sharing electrons
Both end with full orbitals F F
8 Valence electrons

28. F F Covalent bonding Fluorine has seven valence electrons
A second atom also has seven
By sharing electrons
Both end with full orbitals F F
8 Valence electrons

29. Single Covalent Bond A sharing of two valence electrons.
Only nonmetals and Hydrogen.
Different from an ionic bond because they actually form molecules.
Two specific atoms are joined.
In an ionic solid you can’t tell which atom the electrons moved from or to.

30. H O Water Each hydrogen has 1 valence electron
Each hydrogen wants 1 more
The oxygen has 6 valence electrons
The oxygen wants 2 more
They share to make each other happy H O

31. H O Water Put the pieces together The first hydrogen is happy
The oxygen still wants one more H O

32. H O H Water The second hydrogen attaches
Every atom has full energy levels H O H

33. C O Carbon dioxide CO2 - Carbon is central atom ( I have to tell you)
Carbon has 4 valence electrons
Wants 4 more
Oxygen has 6 valence electrons
Wants 2 more C O

34. Carbon dioxide
Attaching 1 oxygen leaves the oxygen 1 short and the carbon 3 short C O

35. Carbon dioxide
Attaching the second oxygen leaves both oxygen 1 short and the carbon 2 short O C O

36. Carbon dioxide
The only solution is to share more O C O

37. Carbon dioxide
The only solution is to share more O C O

38. Carbon dioxide
The only solution is to share more O C O

39. Carbon dioxide
The only solution is to share more O C O

40. Carbon dioxide
The only solution is to share more O C O

41. Carbon dioxide
The only solution is to share more O C O

42. O C O Carbon dioxide The only solution is to share more
Requires two double bonds
Each atom gets to count all the atoms in the bond O C O

43. O C O Carbon dioxide The only solution is to share more
Requires two double bonds
Each atom gets to count all the atoms in the bond
8 valence electrons O C O

44. O C O Carbon dioxide The only solution is to share more
Requires two double bonds
Each atom gets to count all the atoms in the bond
8 valence electrons O C O

45. O C O Carbon dioxide The only solution is to share more
Requires two double bonds
Each atom gets to count all the atoms in the bond
8 valence electrons O C O

46. How to draw them Add up all the valence electrons.
Count up the total number of electrons to make all atoms happy.
Subtract.
Divide by 2
Tells you how many bonds - draw them.
Fill in the rest of the valence electrons to fill atoms up.

47. Examples HCN C is central atom N - has 5 valence electrons wants 8
C - has 4 valence electrons wants 8
H - has 1 valence electrons wants 2
HCN has = 10
HCN wants = 18
(18-10)/2= 4 bonds
3 atoms with 4 bonds -will require multiple bonds - not to H

48. H C N HCN Put in single bonds Need 2 more bonds
Must go between C and N H C N

49. H C N HCN Put in single bonds Need 2 more bonds
Must go between C and N
Uses 8 electrons - 2 more to add H C N

50. H C N HCN Put in single bonds Need 2 more bonds
Must go between C and N
Uses 8 electrons - 2 more to add
Must go on N to fill octet H C N

51. Polar Bonds
When the atoms in a bond are the same, the electrons are shared equally.
This is a nonpolar covalent bond.
When two different atoms are connected, the atoms may not be shared equally.
This is a polar covalent bond.
How do we measure how strong the atoms pull on electrons?

52. Electronegativity
A measure of how strongly the atoms attract electrons in a bond.
The bigger the electronegativity difference the more polar the bond.
Covalent nonpolar
Covalent polar
>1.67 Ionic

53. How to show a bond is polar
Isn’t a whole charge just a partial charge
d+ means a partially positive
d- means a partially negative
The Cl pulls harder on the electrons
The electrons spend more time near the Cl d+ d- H Cl

54. Polar Molecules
Molecules with ends

55. Polar Molecules Molecules with a positive and a negative end
Requires two things to be true
The molecule must contain polar bonds
This can be determined from differences in electronegativity.
Symmetry can not cancel out the effects of the polar bonds.
Must determine geometry first.

56. Is it polar? HF
H2O
NH3
CCl4
CO2

57. Intermolecular Forces
What holds molecules to each other

58. Intermolecular Forces
They are what make solid and liquid molecular compounds possible.
The weakest are called van der Waal’s forces - there are two kinds
Dispersion forces
Dipole Interactions
depend on the number of electrons
more electrons stronger forces
Bigger molecules

59. Dipole interactions Fluorine is a gas Bromine is a liquid
Depend on the number of electrons
More electrons stronger forces
Bigger molecules more electrons
Fluorine is a gas
Bromine is a liquid
Iodine is a solid

60. Dipole interactions
Occur when polar molecules are attracted to each other.
Slightly stronger than dispersion forces.
Opposites attract but not completely hooked like in ionic solids.

61. Dipole interactions H F d+ d- H F d+ d-
Occur when polar molecules are attracted to each other.
Slightly stronger than dispersion forces.
Opposites attract but not completely hooked like in ionic solids.
H F
d+ d-
H F
d+ d-

62. Dipole Interactions
d+ d-
d+ d-
d+ d-
d+ d-
d+ d-
d+ d-
d+ d-
d+ d-

63. Hydrogen bonding
Are the attractive force caused by hydrogen bonded to F, O, or N.
F, O, and N are very electronegative so it is a very strong dipole.
The hydrogen partially share with the lone pair in the molecule next to it.
The strongest of the intermolecular forces.

64. Hydrogen Bonding H O d+ d- H O d+ d-

65. Hydrogen bonding H O H O H O H O H O H O H O

66. MOLECULAR SHAPES OF
COVALENT COMPOUNDS

67. VSepR tHEORY
ALENCE
HELL
VSEPR
LECTRON
AIR
EPULSION

68. This leads to molecules having specific shapes.
What Vsepr means
Since electrons do not like each other, because of their negative charges, they orient themselves as far apart as possible, from each other.
This leads to molecules having specific shapes.

69. Things to remember
Atoms bond to form an Octet (8 outer electrons/full outer energy level)
Bonded electrons take up less space then un-bonded/unshared pairs of electrons.

70. HERE ARE
THE
RESULTING
MOLECULAR
SHAPES

71. Linear BeF2 Number of Bonds = 2
EXAMPLE:
BeF2
Number of Bonds = 2
Number of Shared Pairs of Electrons = 2
Bond Angle = 180°

72. Trigonal Planar GaF3 Number of Bonds = 3
EXAMPLE:
GaF3
Number of Bonds = 3
Number of Shared Pairs of Electrons = 3
Number of Unshared Pairs of Electrons = 0
Bond Angle = 120°

73. Bent #1 H2O Number of Bonds = 2
EXAMPLE:
H2O
Number of Bonds = 2
Number of Shared Pairs of Electrons = 2
Number of Unshared Pairs of Electrons = 2
Bond Angle = < 120°

74. Bent #2 O3 Number of Bonds = 2 Number of Shared Pairs of Electrons = 2
EXAMPLE: O3
Number of Bonds = 2
Number of Shared Pairs of Electrons = 2
Number of Unshared Pairs of Electrons = 1
Bond Angle = >120°

75. Tetrahedral CH4 Number of Bonds = 4
EXAMPLE:
CH4
Number of Bonds = 4
Number of Shared Pairs of Electrons = 4
Number of Unshared Pairs of Electrons = 0
Bond Angle = 109.5°

76. Trigonal Pyramidal NH3 Number of Bonds = 3
EXAMPLE:
NH3
Number of Bonds = 3
Number of Shared Pairs of Electrons = 4
Number of Unshared Pairs of Electrons = 1
Bond Angle = <109.5°

77. NbF5 Trigonal bIPyramidal Number of Bonds = 5
EXAMPLE:
NbF5
Number of Bonds = 5
Number of Shared Pairs of Electrons = 5
Number of Unshared Pairs of Electrons = 0
Bond Angle = <120°

78. OCTAHEDRAL SF6 Number of Bonds = 6
EXAMPLE:
SF6
Number of Bonds = 6
Number of Shared Pairs of Electrons = 6
Number of Unshared Pairs of Electrons = 1
Bond Angle = 90°

79. Metallic Bonds How atoms are held together in the solid.
Metals hold onto there valence electrons very weakly.
Think of them as positive ions floating in a sea of electrons.

80. Sea of Electrons + Electrons are free to move through the solid.
Metals conduct electricity. +

81. Hammered into shape (bend). Ductile - drawn into wires.
Metals are Malleable
Hammered into shape (bend).
Ductile - drawn into wires.

82. Malleable +

83. Malleable
Electrons allow atoms to slide by. + + + + + + + + + + + +

84. THE
END