Packet 7-2

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Transcript Packet 7-2 

Bonding - Atoms interact (with their electrons)
to form compounds.
Sodium
Chlorine
Three Kinds of Bonds:
Ionic
Metal (+)
Nonmetal (-)
Metal transfers electrons to make opposites attract.
Nonmetal
Nonmetal
Covalent
The sharing of electrons creates a strong bond.
Metal
electrons
Metal
Metal
Metal
Metal
Metallic
All electrons are shared in a “sea of electrons.”
2
3
Independent Practice
Fill in the the blanks
C - Covalent
M - Metallic
I - Ionic
4
To understand how bonding works, we need to understand electrons.
Proton
Positive Charge
Neutron
No Charge
Electron
Negative Charge
++
5
Valence Electrons
The electrons on the outer energy level of an atom
How many valence electrons do each of these have?
3
5
2
6
5
1
4
1
6
2
1
H
1.0079
8
8
3
4
Li
Be
6.941
9.012
11
12
Na Mg
22.990
24.305
19
20
K
Ca
39.098
40.08
Do you remember what
the atomic number
represents?
It is the number of protons &
electrons.
2
He
4.003
5
6
7
8
9
10
B
C
N
O
F
10.811
12.011
14.007
15.999
18.998
1.0079
13
14
15
16
17
18
Al
26.982
Ne
Si
P
S
Cl
Ar
28.086
30.974
32.066
35.453
39.948
7
1
H
1.0079
Energy Level 1
2 electrons fit
How many valence electrons does hydrogen have?
How many valence electrons does helium have?
Fill in the periodic table on your paper.
2
He
4.003
Energy Level 2
8 electrons fit:
5
6
7
8
3
4
8
9
Li
Be
B
C
N
O
F
6.941
9.012
10.811
12.011
14.007
15.999
18.998
How many valence electrons
do each of the elements above have?
Fill in the periodic table on your paper.
10
Ne
1.0079
Energy Level 3
8 electrons fit
11
12
13
Na
Mg
22.990
24.305
Al
26.982
14
15
9
16
17
18
Si
P
S
Cl
Ar
28.086
30.974
32.066
35.453
39.948
How many valence electrons
do each of the elements above have?
Fill in the periodic table on your paper.
10
Look at the periodic table. Do you notice a pattern?
What is it?
11
1
2
You should have noticed that each
column has the same number of
valence electrons.
This is true all the way down
the periodic table:
3 4 5 6 7
8
12
But there is something you need to know
about electrons and the energy levels
where they live.
Some are happier, more stable than others.
You see, energy levels like to be FULL.
These are “HAPPY” or “Stable” atoms.
2
He
10
Ne
1.0079
18
Ar
39.948
4.003
Which other atoms are FULL?
Everyone wants to be happy-so, all atoms try to get happy.
But alas, they cannot do it alone. They must
find other atom friends to make them happy.
But the right kind of friend is hard to find -- if you know
what I mean.
•
•
Someone that understands you.
One who is willing to give you what you need most -a part of himself.
13
More on electrons:
Atoms get happy (stable) by filling
up their outer shell of electrons.
Atoms with 4 or more valence electrons
will not give them up!
No, and don’t
ask again!
Which columns on the periodic table
will NOT give away electrons?
Atoms with less than 4 valence electrons
are very generous.
Yes, is there
anything else?
Which columns on the periodic table
will give away electrons?
14
Even MORE about electrons:
15
However this affects their charge…Remember normally:
Have the same
# of Protons (+) = Electrons (-)
If the the blue atom gives up an electron, it becomes (+).
If the yellow atom gives up an electron, it becomes (-).
Lose -e
makes +
Gain -e
makes -
16
1
1+
H
Because of this, we assign a group of elements
an oxidation number.
Compare this number to the valence electrons.
3 4 5 6 7
3+ 4 3- 2- 1- He
2
2+
Be
8
0
Write the oxidation numbers
on your periodic table.
B
C
N
O
F
17
Independent Practice
Fill in the the chart on your paper.
18
Bonding
An atom’s outer electron energy level
is filled by either exchanging or
sharing electrons.
NH3
H
N
NaCl
H
Na
Cl
H
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Ionic Bonds
Metal to Nonmetal
Electrons either taken or given away
Sodium
+
Chlorine
Opposites attract
Ionic Bonds
Metal to Nonmetal
Sodium gives Chlorine 1 electron.
Na
Cl
Sodium is happy at energy level 2.
Chlorine is happy at energy level 3.
Sodium
NaCl
Chlorine
Sodium Chloride
20
Covalent
21
non-metal + nonmetal
Nitrogen
Electrons are shared.
Hydrogen
Hydrogen
H
NH3 Ammonia
H
Hydrogen
N
H
22
-e
Ag+
-e
metal
metal
metal
Metallic
Share in a sea of electrons
-e
Ag+
-e
Ag+
-e
Ag+
-e
-e
Ag+
-e
Ag+
-e
-e
Ag+
Ag+
-e
-e
-e
Ag+
23
Independent Practice
Fill in the the chart on your paper.
0
1+
2+
When you combine atoms, 3+ 4
you use the oxidation
numbers to help you figure
out the ratio.
3- 2- 1-
Oxidation Number
Varies
Simply switch the oxidation number to get the correct
subscript. Put the #s in lowest terms if necessary.
+2O-2
Mg1+2Cl-1
Mg
2
2 = 2
MgCl2
MgO
Fe2+3 O-2
3
Fe2O3
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25
Independent Practice
Fill in the the chart on your paper.
Polyatomic Compounds:
26
Compounds that Act as a Unit
Charge
1+
1111223-
Mg+2 PO43
3
2
Mg3(PO4)2
Name
Ammonium
Acetate
Chlorate
Hydroxide
Nitrate
Carbonate
Sulfate
Phosphate
Formula
NH4+
C2H3O4ClO3
OHNO3CO32SO42PO43-
Li+2 SO42
2
2
LiSO4
Fe+3 NO4-2
2
3
Fe2 (NO4)3
Note the ( ) on multiple polyatomic ions.
27
Independent Practice
Fill in the the chart on your paper.
Naming Compounds
28
Rules for naming binary (meaning 2 types of atoms) ionic
compounds:
Example: KBr
1. Write the name of the metal first.
2. Write the name of the nonmetal changing the ending to “ide.”
Potassium Bromine
Bromide
29
Independent Practice
Fill in the blanks.
Naming Compounds
Rules for naming binary ionic compounds:
(Binary means 2 types of atoms.)
Example: CuCl
1. Write the name of the metal first.
2. Write the name of the nonmetal changing the ending to “ide.”
3. If the metal is a “transition metal,” the oxidation number
varies. Therefore, to name the compound we must put the
ionic charge in parentheses. For example:
Copper (I) Chlorine
Chloride
because the oxidation of chlorine is 1.
30
31
Independent Practice
Fill in the blanks.
Naming Compounds
Polyatomic
Charge
1+
1111223-
Name
Ammonium
Acetate
Chlorate
Hydroxide
Nitrate
Carbonate
Sulfate
Phosphate
Formula
NH4+
C2H3O4ClO3
OHNO3CO32SO42PO43-
Rules for naming polyatomic ionic compounds:
1. Write the name of the metal first.
2. Write the name of the polyatomic nonmetal from the chart.
Example: K2 SO4
Potassium Sulfate
32
Naming Compounds
33
Ionic
Rules for naming polyatomic ionic compounds:
Charge
1+
1111223-
Name
Ammonium
Acetate
Chlorate
Hydroxide
Nitrate
Carbonate
Sulfate
Phosphate
Formula
NH4+
C2H3O4ClO3
OHNO3CO32SO42PO43-
If the polyatomic ion is first, then:
1. Use the chart above to name the metal.
2. Write the name of the nonmetal changing the ending to “ide.”
Example: NH4Cl
Ammonium Chloride