my name is bond… chemical bond. chemical bonding chapter 6
TRANSCRIPT
My Name is Bond…
Chemical Bond
Chemical Bonding
Chapter 6
Why does bonding occur?
Knowing what you know about the stability of atoms…. Why do atoms want to form bonds?
Why do atoms form bonds??
• Why do atoms form bonds??
• To become more stable.
Visual Concepts – to lower potential energy.
Types of Bonding
• Ionic– Transfer of electrons from one atom to
another
– Cations and anions attracting each other by opposite charges (electrostatic bond)
– Metal bonds with nonmetal
Visual Concepts
Covalent
Sharing of electrons between the atoms
Nonmetal bonds with nonmetal
Visual Concepts
What is the general rule?
Back to Bonding!
How did you do on the POGIL?
Review…
Electronegativity: a measure of the ability of an atom in a chemical bond to attract electrons from
another atom in that bond.
Determining bond type using electronegativity differences…
• If the difference is < 1.67 a covalent bond forms.
• If the difference is > 1.67 an ionic bond forms.
Ex. Cl – Ca
Ex. Cl – Br
Let’s look at some ionic compounds…
Draw the molecular orbital diagrams for sodium and fluorine.
How would the electrons transfer?
One unit of an ionic compound is a formula unit.
Draw the molecular orbital diagrams for calcium and chlorine.
How many chlorine atoms are needed to make calcium stable?
Criss-Cross Method
We can determine the formula for a neutral ionic compound by looking at the charge of each atom.
Naming Ionic Compounds
Name the metal first….
Name the nonmetal…..
change the end to “ide”
NaCl
Sodium Chloride
Determine the neutral formulas and names for the following formula units.
F P S I
Be
K
Ba
Cs
Warm Up
Nickel has several stable isotopes. Below are the mass and percent abundance. Calculate the average atomic mass.
Ni-58 68.08%
Ni-60 26.22%
Ni-61 1.140%
Ni-62 3.635%
Ni-65 0.9255%
Questions on Bonding WS1 and WS2?
Wonder Project Grading
You should have turned in your final project yesterday!
Now you get to help me grade them!
Go to my website, unit 3, Wonder Project grading and follow the directions.
Missing Work by 12/13
Vocabulary Terms
Formula Unit- one molec..(oh! We can’t say that!) 1 unit of an ionic compound.
Electrostatic force - the force that occurs when a + charge is attracted to a - charge (causes the bonds!)
Salt- another name for ionic compounds
Characteristics of Ionic Compounds
• Crystal lattice is made of formula units, which repeat in a geometric pattern
• Creates a stable structure
Visual Concepts
Characteristics of Ionic Compounds
High melting and boiling points.
Hard and brittle
Many ionize in water- become good conductors.
Ionic Bonding with Transition Metals….
How would we name the following ionic compounds?
NiCl
NiCl2
Transition metals can have more than one charge… here is where it gets a little tricky!
Ionic Bonding with Transition Metals….
Determine the neutral compound…
Fe 3+ and Cl1-
The charge of the METAL is indicated using a roman numeral after the name.
1+ (I)
2+ (II)
3+ (III)
4+ (IV)
5+ (V)
Practice on your WS
Ionic Equations
How is the formula unit going to dissociate in water?
Barium chloride
Calcium nitride
Cobalt (III) oxide
You can do the following on Bonding WS 4
1, 2, 6, 7,10
Warm Up: Name the following compounds…
CrO
Cr2O3
FeCl2FeCl3NiS
CoCl3
Now try going from name to formula!
Ionic Bonding with Polyatomic Ions
Polyatomic Ions are covalently bonded groups of atoms that have a charge…..
Formula Units with Polyatomic Ions…what is the charge for each?
NO3 SO3 CN 02
CaKBa
Name the metal… name the polyatomic ion
Exceptions
All d block elements get a roman numeral
EXCEPT Zn2+, Cd2+, Ag1+
Metals in the p block- No roman numerals
EXCEPT Sn and Pb.
Homework
Finish Bonding WS4
Start Criss Cross- Determine molar mass for these 10. Names for all of them!
Lewis Structures…
Represents the valence electrons on the atoms with dots… top, side, bottom, side
Visual Concepts
Lewis Structures for Ionic Cmpds
Draw the Lewis Structures for K and Br. Show the movement of electrons when the bond forms.
Why is each atoms stable?