Title: TYPES OF CHEMICAL BONDS
1TYPES OF CHEMICAL BONDS
- IONIC BONDS
- COVALENT BONDS
- HYDROGEN BONDS
- METALLIC BONDS
2IONIC BONDING
3IONIC 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
4IONIC BONDING
IS THE COMPOUND AN IONIC COMPOUND?
Mg N
3
2
5IONIC 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.
6IONIC BONDING
- Metals will tend to lose electrons and become
- POSITIVE CATIONS
7IONIC BONDING
- Nonmetals will tend to gain electrons and become
- NEGATIVE ANIONS
8Properties 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.
9Crystalline structure
The POSITIVE CATIONS stick to the NEGATIVE
ANIONS, like a magnet.
10Do 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.
- Melting points always above 800ºC.
- Dissolved in water they conduct.
11Ionic solids are brittle
12Ionic solids are brittle
- Strong Repulsion breaks crystal apart.
13COVALENT BONDING
14COVALENT 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
15COVALENT 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
16COVALENT BONDING
IS THE COMPOUND A COVALENT COMPOUND?
C O
2
YES since it is made of only nonmetal elements
17Covalent bonding
- Fluorine has seven valence electrons
18Covalent bonding
- Fluorine has seven valence electrons
- A second atom also has seven
19Covalent bonding
- Fluorine has seven valence electrons
- A second atom also has seven
- By sharing electrons
20Covalent bonding
- Fluorine has seven valence electrons
- A second atom also has seven
- By sharing electrons
21Covalent bonding
- Fluorine has seven valence electrons
- A second atom also has seven
- By sharing electrons
22Covalent bonding
- Fluorine has seven valence electrons
- A second atom also has seven
- By sharing electrons
23Covalent bonding
- Fluorine has seven valence electrons
- A second atom also has seven
- By sharing electrons
24Covalent bonding
- Fluorine has seven valence electrons
- A second atom also has seven
- By sharing electrons
- Both end with full orbitals
25Covalent 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
26Covalent 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
27Single 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 cant tell which atom the
electrons moved from or to.
28Water
- 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
29Water
- Put the pieces together
- The first hydrogen is happy
- The oxygen still wants one more
H
30Water
- The second hydrogen attaches
- Every atom has full energy levels
H
H
31Multiple Bonds
- Sometimes atoms share more than one pair of
valence electrons. - A double bond is when atoms share two pair (4) of
electrons. - A triple bond is when atoms share three pair (6)
of electrons.
32Carbon dioxide
- CO2 - Carbon is central atom
- Carbon has 4 valence electrons
- Wants 4 more
- Oxygen has 6 valence electrons
- Wants 2 more
C
33Carbon dioxide
- Attaching 1 oxygen leaves the oxygen 1 short and
the carbon 3 short
C
34Carbon dioxide
- Attaching the second oxygen leaves both oxygen 1
short and the carbon 2 short
C
35Carbon dioxide
- The only solution is to share more
C
36Carbon dioxide
- The only solution is to share more
C
37Carbon dioxide
- The only solution is to share more
C
O
38Carbon dioxide
- The only solution is to share more
C
O
39Carbon dioxide
- The only solution is to share more
C
O
40Carbon dioxide
- The only solution is to share more
C
O
O
41Carbon dioxide
- The only solution is to share more
- Requires two double bonds
- Each atom gets to count all the atoms in the bond
C
O
O
42Carbon 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
C
O
O
43Carbon 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
C
O
O
44Carbon 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
C
O
O
45Coordinate Covalent Bond
- When one atom donates both electrons in a
covalent bond. - Carbon monoxide
- CO
46Coordinate Covalent Bond
- When one atom donates both electrons in a
covalent bond. - Carbon monoxide
- CO
O
C
47Coordinate Covalent Bond
- When one atom donates both electrons in a
covalent bond. - Carbon monoxide
- CO
O
C
48Coordinate covalent bond
49Polar 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?
50Electronegativity
- A measure of how strongly the atoms attract
electrons in a bond. - The bigger the electronegativity difference the
more polar the bond. - 0.0 - 0.3 Covalent nonpolar
- 0.3 - 1.67 Covalent polar
- gt1.67 Ionic
51How to show a bond is polar
- Isnt a whole charge just a partial charge
figure it out by drawing LEWIS STRUCTURES - d means a partially positive (no lone pairs)
- d- means a partially negative (atom has lone
pairs) - The Cl pulls harder on the electrons
- The electrons spend more time near the Cl
d
d-
H
Cl
52Polar 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.
53Is it polar?
54Intermolecular Forces
- What holds molecules to each other
55Intermolecular Forces
- They are what make solid and liquid molecular
compounds possible. - The weakest are called van der Waals forces -
there are two kinds - Dispersion forces
- Dipole Interactions
- depend on the number of electrons
- more electrons stronger forces
- Bigger molecules
56Dipole interactions
- 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
57Dipole 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.
58Dipole 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.
59Dipole Interactions
d d-
60Hydrogen 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.
61Hydrogen Bonding
62Hydrogen bonding
63Metallic 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.
64Sea of Electrons
- Valence electrons are free to move through the
solid. - Metals conduct electricity.
65Metals are Malleable
- Hammered into shape (bend).
- Ductile - drawn into wires.
66Malleable
67Malleable
- Electrons allow atoms to slide by.