Transcript Chapter 11

Chapter 6
Chemical Bonds
Compounds
H
+
O
H
H2O
-
Compounds
H
Cl
HCl
Outer Energy Level
Atom
is stable: outer energy level is
filled.
 Eight(8) electrons. (2 e- for first level.)
The outer energy level is called the
valence shell.
Electrons in the outer shell are called
Valence Electrons.
Electron Dot Diagram
Represent Valence Electrons
N
Group 15 – 5A
5 Valence e
Stable Atoms
He
Kr
Ne
Ar
Xe
Rn
Valence Electrons
Group 1(1A)
1 valence e-
Cs
Valence Electrons
Group 2 (2A)
2 valence e-
Ca
Valence Electrons
Transition
Elements
For
This
Class
Valence Electrons
Ga
Group 13 (3A)
3 valence
e
Valence Electrons
Sn
Group 14 (4A)
4 valence
e
Valence Electrons
P
Group 15 (5A)
5 valence
e
Valence Electrons
S
Group 16 (6A)
6 valence
e
Valence Electrons
I
Group 17 (7A)
7 valence
e
Valence Electrons
Ne
Group 18 (8A)
8valence
e
Making Atoms Stable
Transferred!
Na
Cl
+
Na Cl
Making Atoms Stable
Cl
Cl
Shared
Cl Cl
Kinds of Chemical Bonds
Electron
Loss, Gain or Share
Ionic Bonds
Ion
The charged particle that results
when an atom
gains or loses
one or more electrons.
Anion
Anions
are the result of atoms
gaining electrons.
Anions have a negative charge.
Br
+
35p
35e
36e
Anion
Atoms
change their name on
becoming an anion.
“ide” is added to their name.
o
Bromine Bromide
+
9p
9e
Ion
+
9p
10e
Gain
e-
F
Fluorine
F
Fluoride
Cation
Cations
are the result of atoms
losing electrons.
Cations have a positive charge.
+
2
+
Ca
20p
20e
18e
+
3p
3e
Li
Ion
Lose
e-
+
3p
2e
+
Li
Lithium
Ionic Bonding
Bonding that occurs between
ions or the
losing or gaining
electrons.
Ionic Bond
Na
Cl
Na Cl
NaCl
Sodium
Na loses one electron becomes Na +1
Chlorine
Cl gains one electron becomes Cl -1
Result
Sodium Chloride - Na Cl
Ionic Bonding
Cl
Cl
Ca
Cl Ca Cl
CaCl2
Calcium
Ca loses two electrons becomes Ca 2+
Chlorine
Cl gains one electron becomes Cl Result
Calcium Chloride – CaCl2
Ionic Bond
Metals
tend to lose electron.
Non-metal tend to gain electrons.
Metals
combine with
Non-metals
Ionization Energy
The amount of energy needed to
remove an electron from an atom.
Crystal Lattices
Solids whose
particles arrange
in a lattice
structure.
Properties of Ionic Compounds
 Strong Attraction
between Ions.
 High
Melting Point (Solid)
 Shatter (Crystal)
 Melted or Dissolved
Good
Conductor of Electricity
Homework 6-1
Section 6-1: Worksheet
Electron Dot Worksheet
Due 12/9/08
Covalent Bond
Atoms that combine by
sharing electrons.
Electron Sharing
Cl2
Cl
Cl
Making Atoms Stable
Cl
Cl
Shared
Cl Cl
Shared
H+O+H
H2O
H
H
Shared
O
Multiple Covalent Bonds
Atoms that share more than
one pair of electrons.
O + O
O2
Shared
O
O
O O
Double Bond
N + N
N2
Shared
N N
N N
Triple Bond
Molecule
A neutral particle that is formed
when atoms bond covalently.
Unequal Sharing of Electrons
Different
elements do not share
electrons evenly.
As you go left to right in the periodic
table, elements have a greater
attraction to electrons.
N C
Unequal Sharing of Electrons
Molecule
that are formed have
polarity.
The molecule formed will have a
positive side and a negative side.
Polar Molecules
+
δ
delta
H
Cl
δ
Chlorine attracts e- more!!
Polarity ???
Type
of Atoms
Shape of Molecule
Polar
+
δ
δ
C
O
+
δ
Polar
H
+
δ
δ
+
δ
H
O
O2
Non-Polar
O
δ
+
δ
C
O
+
δ
δ
Non-Polar
+
δ
CH4
+
δ
+
δ
δ
+
δ
+
δ
NaCl
Not a Molecule
Attraction between Molecule
+
δ
δδ+
Attraction between Molecule
Non-Polar – weaker attraction
•Lower Boiling Point – Gas
•Evaporate quickly
•Low Surface Tension
Attraction between Molecule
Polar – Greater attraction
•Higher Boiling Point – Liquid
•Evaporate slower
•Higher Surface Tension
Homework 6-2
Section 6-2
Worksheet
Due 12/10/08
Section 6-3
Naming Compounds
and
Writing Formulas
Naming Binary Compounds
Binary Compounds
Two Elements
Rules for naming
Binary Compounds.
Begin with the Cation
(Positive Charge)
The Anion (-) is changed
to end in ”ide”.
Binary Compounds
Chlorine and Magnesium
Magnesium Chlorine –
+
2
- Cation
1 - Anion
Magnesium Chloride
Binary Compounds
Sodium and Sulfur
Sodium Sulfur –
+
1
- Cation
2 - Anion
Sodium Sulfide
Binary Compounds
Lithium and Oxygen
Lithium -
+
1
Oxygen –
- Cation
2 - Anion
Lithium Oxide
Metals with Multiple Ion
(Transition Metals)
+
Cu
2+
Cu
Copper(I)
Copper(II)
Copper and Oxygen
+
2Cu O
Cu2O
Copper(I) Oxide
Copper and Oxygen
2+
2Cu O
Cu O
Copper(II) Oxide
Polyatomic Ions
A group of covalently bonded
atoms that act as one charged
atom. These ions can combine
with other elements and ions.
Examples of Polyatomic Ions
Ammonium
NH4
N
H
(3-) + 4(1+) = 1+
+
(NH4)
Examples of Polyatomic Ions
Hydroxide
OH
O
H
(2-) + (1+) = 1-
(OH)
Carbonate
CO3
C
O
(4+) + ((2-)X3)
(4+) + (6-) = 2-
(CO3
2)
Writing formulas
for
Ionic Compounds
Example #1
Write the chemical formula for the
compound of silver and sulfur.
Silver Ag 1+ Sulfur: S 2(? X 1) + (?X-2) = 0
(2 X 1) + (1X-2) = 0
Ag2S
Example #2
Write the chemical formula for the
compound of aluminum and oxygen.
Aluminum: Al 3+ Oxygen: 0 2(? X +3) + (?X-2) = 0
(2 X +3) + (3X-2) = 0
Al203
Crisscross Method
Write the chemical formula for the
compound of boron and sulfur.
3+
B S
B2 S3
2-
Crisscross Method
Write the chemical formula for the
compound of sodium and phosphorus.
+
Na P
Na3P
3-
Find the formula for calcium hydroxide.
Ca
2+
OH
Ca(OH)2
1-
Describing Molecular Compounds
The name and formula of a molecular
compound describe the type and
number of atoms in a molecule of a
compound.
Naming Molecules
In
general, the most metallic element
appears first. (Left and bottom in Periodic
Table)
Second element change ending to “-ide” .
Use prefixes to tell how many.
If there is only one of the first element no
prefix is used.
Prefixes for Naming Molecules
# Atoms Prefix # Atoms Prefix
1
mono-
6
hexa-
2
di-
7
hepta-
3
tri-
8
octa-
4
tetra-
9
nona-
5
penta-
10
deca-
Name these molecule
CO
Carbon
Monoxide
Name these molecule
CO2
Carbon
Dioxide
Name these molecule
N 2O4
Dinitrogen Tetraoxide
Name these molecule
P2 O
Diphosphorus
5
Pentaoxide
Writing Molecular Formulas
Diphophorus Tetra fluoride
P2 F4
Homework 6-3
Section 6-3
Worksheet
Due 12/16/08
Structures of Metals
A metallic bond is the attraction
between a metal cation and the
shared electrons that surround it.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
Sea of Valence Electrons
The negatively charged
electrons act as a "cement" that
hold the positively charged
metal ions in their relatively
fixed positions.
Metals are good Conductors of
Heat and Electricity
This is directly due to the
mobility of the electrons.
Metal Hardness
The "cement" effect of the
electrons determines the
hardness of the metal.
Metal Luster
This is due to the uniform way
that the valence electrons of the
metal absorb and re-emit light
energy.
Metal are
Malleable and Ductile
The metal cations and electrons
can "flow" around each other,
without breaking the crystal
structure.
Ductile
Alloys
An alloy is a mixture of two or
more elements, at least one of
which is a metal.
Scientists can design alloys
with specific properties by
varying the types and
amounts of elements in an
alloy.
Copper Alloys
Steel Alloys
Homework 6-4
Finish Packet
Due 12/19/08
Test: 12/23/08
Project: 12/22/08
Corrosive
“Tear Apart”
Recycle
Homework 3-14
Section 11-3 Wrap-up
Page: 313
Worksheet
Due 3/6/06
Writing Formulas
Oxidation Numbers
The name given to the combining
ability of an atom.
Oxidation Numbers
Na
Na
11p+
11e-
11p+
1+
10e-
Oxidation Numbers
F
F
9p+
9e-
9p+
1-
10e-
Oxidation Numbers
N
N
7p+
7e-
7p+
3-
10e-
Oxidation Numbers
N
N
7p+
7e-
7p+
3-
10e-
2+
Ca
Ca
20p+
20e-
20p+
18e-
Metals
Group
Oxidation Number
1
1+
2
2+
3-12
Transition Elements
tend to have
more than one
13
3+
14
2+ or 4+
Nonmetals
Group
Oxidation Number
15
3-
16
2-
17
1-
Homework 11-4
Practice Problems: 1-2
Page: 316,318
Due 3/15/04
Homework 11-5
Practice Problems: 1-2
Page: 318
Due 3/17/04
Hydrated Crystals
Hydrate: Crystal containing a definite
number of water molecules.
H20
H20
H20
CuSO4
H2O
CuSO4  5 H2O
H20
Anhydrous
A compound with no water.
1
Na
Cl
1+
Na
1Cl
NaCl
2
F
Ca
2+
Ca
1F
CaF2
F
3
O
Al
O
Al
O
3
3+
Al
2O
Al2O3
4
H
+
H
N
3N
H3 N
H
H
5
K
S
+
K
2S
K2 S
K
6
2+
Ca
NO3
-
Ca(NO3)2
7
2+
Mg
SO4
MgSO4
2-
8
3+
Ga
CO3
2-
Ga2(CO3)3
9
+
NH4 PO4
3-
(NH4)3PO4
10
+
Na
NO2
NaNO2
-