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Starter S-53
Mole Day!
Mole Day!
Starter S-55
What is the value of a mole?
What is that number used for?
Ionic and Metallic Bonding
Chapter 7
7.1 Ions
Chapter 7
Valence Electrons – highest energy electrons
Groups always have the same number of valence electrons
7.1 Ions
Valence electrons are related to the group
Valence electrons are usually the ones involved in chemical bonding
7.1 Ions
Octet Rule
Metals tend to lose their valence electrons leaving a complete octet in the next lowest energy level
Nonmetals tend to gain or share electrons to complete their octet
7.1 Ions
Ionic Bonding
Ionic Bonding involves the formation of a
Cation – lose electrons
Anions – gain electrons
7.1 Ions
Formation of Ions
Electron configuration change in cation formation
7.1 Ions
Al
3s 3p 3d
2s 2p
1s
Al+3
Lower Octet
Electron configuration change in anion formation
7.1 Ions
S
3s 3p 3d
2s 2p
1s
S-2
New Octet
Oxidation Number – apparent charge in a compound
7.1 Ions
Starter S-57
What is an ion?
How many electrons does Oxygen need in its outer energy level to be stable?
Why does Helium only need two electrons to be stable?
7.2 Ionic Bonds and Ionic Compounds
Chapter 7
Ionic Compounds – composed of cations and anions
One element give electrons to the other element
7.2 Ionic Bonds and Ionic Compounds
Writing formulas for ionic compounds
The sum of the charges always equals 0
Usually if we flip the
number values
So the formula would be
7.2 Ionic Bonds and Ionic Compounds
2 1 1
2 1 1 0
Ca Cl Cl
2CaCl
Positive ion is always written first
Numbers are written after the element and as a subscript
The number 1 is never written
7.2 Ionic Bonds and Ionic Compounds
Try Aluminum and Oxygen
Calculations
Formula
7.2 Ionic Bonds and Ionic Compounds
3 3 2 2 2
3 3 2 2 2 0
Al Al O O O
2 3Al O
Formulas are always given as smallest ratio so
Calculations
Formula
7.2 Ionic Bonds and Ionic Compounds
4 4 2 2 2 2
4 4 2 2 2 2 0
Pb Pb O O O O
2 4Pb O
Pb+4 O-2
2PbO
Formula Unit – the smallest whole number ratio of ions
Ionic Compounds are
really repeating structures
7.2 Ionic Bonds and Ionic Compounds
Properties of Ionic Compounds
1. Most are crystalline solids at room temperature
2. Generally have high melting points
3. Conduct an electric current when melted or dissolved
7.2 Ionic Bonds and Ionic Compounds
Starter S-59
What is the formula for
1. Vanadium (VI) and Oxygen
2. Vanadium (V) and Oxygen
3. Lead (IV) and Sulfur
4. Lead (II) and Sulfur
7.3 Bonding in Metals
Chapter 7
In metals valence electrons are free to move around
The individual atoms are free to slide past each other
Explains conductivity – electrons are free to move
7.3 Bonding in Metals
Bonding Animation
Ductility and Malleability – metals free to slide past each other
Metals are arranged in compact and orderly crystal patterns
Body Centered Cubic-every atom has eight neighbors
Na, K, Fe, Cr, W
7.3 Bonding in Metals
Crystal Structures
Face Centered Cubic – every atom has 12 neighbors
Cu, Ag, Au, Al,
Pb
Hexagonal Close Packed – 12 different pattern
Mg, Zn, Cd
7.3 Bonding in Metals
Alloys – mixtures composed two or more elements, at least one of which is a metal
Sterling silver
92.5% silver, 7.5% copper
Harder, more durable than Ag
Bronze
87.5% copper, 12.5% tin
Harder, more easily cast
7.3 Bonding in Metals
Steel
Stainless Steel (80.6% Fe, 18.0% Cr, 0.4% C, 1.0 % Ni)
Spring Steel (98.6% Fe, 1.0% Cr,
0.4% C)
7.3 Bonding in Metals
Surgical Steel (67% Fe, 18% Cr, 12% Ni, 3% Mo)
7.3 Bonding in Metals
Starter S-60
What is the chemical formula of
A. Iron (III) and Chlorine
B. Calcium and Fluorine
C. Sodium and Oxygen