Name: ____________________________________________ Period: _________ 2011

Bonding and NomenclatureIonic, Covalent, and Metallic bonding

Fill the calendar in each class.Day Date In class topic and pages Quiz Homework

If you are absent for any reason, it is your responsibility to check the calendar on my website to see what you missed BEFORE you return to class: www/austinisd.org/staff/2348

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Properties of Metals and Metallic BondingMetal atoms are held together by Metallic “Bonds.” The valence electrons of metal atoms can drift freely from one part of the metal to another- this is called a ___________________________________. Metallic bonds consist of the attraction between free floating electrons and the positively charged metal nuclei. This attraction is the “bond” that holds metals together.

A. Electrons move freely through metal like a negative "glue" holding cations together.

B. Free electrons can move rapidly, hence metals are good conductors of __________________.

C. Free electrons transmit kinetic energy rapidly, hence metals are good conductors of _______.

D. The layers of atoms in metal are hard to pull apart because of the electrons holding them together, but individual atoms are not held to any other specific atoms, so atoms slip easily past one another. This makes metals __________________ and _____________________.

Pick any 3 metals from the s or d block. Metal 1: Metal 2: Metal 3:

Write the shorthand electron configuration for each metal you chose and circle the valence electrons.Make a dot diagram for this element based on the valence electrons above.Atoms are chemically stable if they have 8 valence electrons. Will these metals gain or lose electrons to become stable?

Therefore, a chemical property of metals is that they ____________ electrons to become chemically stable, so they become _____________ in chemical reactions. They react with ______________ in air to form metallic oxides, and with ________________ to form salts.

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ALLOYSVery few metals that you encounter daily are pure metals. Most metals are alloys, homogeneous mixtures (solutions) of two or more elements of which at least one is a metal. Alloys are important because their properties are often superior to those of their component elements.

Examples:

Brass is an alloy of copper (65%) and zinc (35%). Brass is harder and easier to shape than either copper or zinc.

Sterling silver is an alloy of silver (92%) and copper (8%). Sterling silver is harder and more durable than pure silver, but still soft enough to make jewelry.

Stainless steel is an alloy of iron (81%), chromium (18%), nickel (1%), and trace amounts of carbon.Stainless steel does not rust or corrode as fast as ordinary steel.

Label the cations in each picture above to represent the percentage of metals present in each alloy.Formative Assessment: Identify the following as alloys or pure elements.1) 24k gold___________________2) Steel___________________3) Aluminum________________4) Bronze___________________

5) Copper___________________6) Iron___________________7) Zinc___________________8) Cast iron__________________

9) Amalgam__________________10) Pewter__________________11) Solder__________________12) Sterling silver____________

**************************************************************************************************Alchemy Lab

Pre-Lab ThoughtsImagine putting some milk chocolate chips and some white chocolate chips in a pan over low heat and stirring it.What changes would you observe? Would the end result of this process be a mixture or a

pure substance? Explain.

Data TableCondition AppearanceUntreated penny

Treated pennies

Treated pennies that were then heated

Conclusion: Is this Alchemy?Explain what you think happened to make the pennies “gold.”

Were the changes to the pennies chemical or physical changes? Why do you think this?

What type of bonds (if any) were formed?

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BONDING INQUIRY ACTIVITYFor each of the following substances, place the symbol of the first element in its spot on the periodic table using red ink. Then, place the symbol of the second element in the substance in its spot on the periodic table using black ink.

SUBSTANCE GROUP I: NaCl LiBr KI ZnCl2 Fe2O3 CuO AlF3

QUESTIONS FOR SUBSTANCE GROUP I:1. What “classification” would you give the first (red) elements? Metal or Non-Metal?

2. What “classification” would you give the second (black) elements? Metal or Non-Metal?

Complete the sentence: Group I compounds contain _______________________________________.

For each of the following substances, place the symbol of the first element in its spot on the periodic table using red ink. Then, place the symbol of the second element in the substance in its spot on the periodic table using black ink.

SUBSTANCE GROUP C: CCl4 P2S5 N2O4 NI3 H2S OF2 SeBr2

QUESTIONS FOR SUBSTANCE GROUP C:1. What “classification” would you give the first (red) elements? Metal or Non-Metal?

2. What “classification” would you give the second (black) elements? Metal or Non-Metal?

Complete the sentence: Group C compounds contain _______________________________________.

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Laboratory ObservationsDid crystals of this type

of compound melt?Are they electrolytes (did solutions containing

this type of compound dissolved in water conduct electricity)?

Substance group I

Substance group C

Electronegativity and Bond Type: use the chart below to calculate the difference in electronegativity and then use the Bond character reference chart below to identify the type of bond present.

Formulas from substance group I

Difference in electronegativity Bond type

Formulas from substance group C

Difference in electronegativity Bond type

NaCl CCl4

LiBr P2S5

KI N2O4

ZnCl2 NI3

Fe2O3 H2S

CuO OF2

AlF3 SeBr2

Complete the following sentences:

Group I contains mostly ___________________________ bonds.

Group C contains mostly ___________________________ bonds.

Types of Particles

Bond character reference chartdifference in

electronegativitybond type

0-0.5 covalent0.51-1.69 polar covalent

1.70 and higher ionic

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Substance group I is made of anions and cations that alternate in crystals. The smallest “particle” of this is a formula unit.

Substance group C is made of covalently bonded atoms that have no charge. The smallest particle is a molecule.

Lewis Dot Structures and Bond Formation: Use the transparencies of dot diagrams to combine the following elements in order to make each atom chemically stable. Then draw the resulting combination in the space below. Use a line to represent shared electrons, and write charges on atoms that gain or lose electrons.Lithium and fluorine Magnesium and oxygen Magnesium and chlorine

Chemical formula: Chemical formula: Chemical formula:Name: Name: Name:Hydrogen and oxygen Sulfur and chlorine Nitrogen and hydrogen

Chemical formula: Chemical formula: Chemical formula:Name: Name: Name:Chlorine and chlorine Oxygen and oxygen Nitrogen and nitrogen

Chemical formula: Chemical formula: Chemical formula:Name: Name: Name:

1. What type of elements are represented by hollow letters?_________________ solid letters? _________________2. Circle or highlight the type(s) of elements that share their valence electrons when they combine: Metals Nonmetals3. Circle or highlight type(s) of elements that donate or transfer electrons when they combine: Metals Nonmetals4. Which combination of elements (from #2 and 3) could be called covalent? (hint: co – valence)___________________5. Which combination of elements (from #2 and 3) could be called ionic? (hint: form ions) ________________________6. Which type of bond holds the diatomic elements together in molecules? Ionic Covalent 7. Which element is the exception to the octet rule (does not need 8 electrons to be stable)?___________________8. In the IONIC combinations, determine the charge of each atom AFTER the transfer of electrons. For the overall

combination, what do the charges add up to?_____________________

HOW TO WRITE BINARY IONIC FORMULAS CHARGES!!1. Write the symbol for the METAL with the correct oxidation number (charge).2. Write the symbol for the NONMETAL with the correct oxidation number (charge).3. Use the least common multiple of the ions’ charges to determine how many of each ion are needed to

make the combination NEUTRAL (add up to 0).

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4. Write each symbol (WITHOUT CHARGES) and put subscripts after each symbol showing how many of each ion was needed.

5. Check to make sure they are in the lowest possible whole-number ratio. If not, reduce them.Examples: Tin (IV) oxide Strontium nitride Sodium fluoride

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HOW TO WRITE COVALENT BINARY FORMULAS NO CHARGES!!1. Write the symbol for the element in the lowest numbered group first. (exceptions – hydrogen always

comes after carbon, and halogens always come before oxygen)2. If there is a prefix, “translate” it and write the number as a subscript after the symbol. 3. Write the symbol for the other element. If there is a prefix, “translate” it and write the number as a

subscript after the symbol.Examples: Nitrogen dioxide Carbon tetrafluoride Dihydrogen monoxide

Practice: Writing Chemical Formulas and Identifying Types of Bonds If the compound contains a metal, write its formula using ionic compound rules, even if the bond is polar covalent.

Name of Compound Chemical Formula Electronegativity Difference Type of BondCarbon monoxide

Lithium chloride

Calcium oxide

Chromium(III) sulfide

Dinitrogen tetroxide

Iron(II) bromide

Phosphorus trichloride

Potassium sulfide

Calcium iodide

Nitrogen triiodide

COVALENT BONDING AND THE OCTET RULECovalent compounds are held together by a ___________ of electrons – NOT by an electrical attraction. Single bonds are __ shared electrons; double bonds are __ shared electrons; and triple bonds are __ shared electrons.

To draw Lewis structures for covalent bonds, use the Needed-Available-Shared (NAS) method:1. N (Needed): Find the number of electrons needed to form full octets for all elements involved. For most nonmetals,

the number needed is 8. Hydrogen is one exception, it needs only 2.2. A (Available): Find the number of available electrons by adding up all the valence electrons for all atoms involved.3. S (Shared): Subtract the two numbers. S = N-A A bond is formed with two electrons, so divide the number of

shared electrons by 2 to tell you how many bonds to draw between the elements. B = S÷24. Draw the molecule. Put the least electronegative atom in the center. Hydrogen is never the central atom. Draw in

the bonds, then draw in the rest of the lone pairs of electrons to complete each atom’s octet.5. Check to ensure all atoms have a full octet (eight electrons, either their own or shared).

Example #1: CO2

N=A=S=

Example #2: CH4

N=A= S=

Example #3: N2 N= A= S=

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Substance Group I = Ionic Compounds-Contain _________________________________-Electrons are_________________between atoms-Bonds are _______________________________-Particles are______________________________.

-__________________________________at room temperature.-Solids have a ________ melting point.-__________________________: solutions of this compound ______ conduct electricity.-Electronegativity difference is _______________ than 1.70 Paulings.-The only type of compound to contain a _______. -Made of _________ whose charges add up to __.-When writing ionic formulas:________________ _________________________________________-When naming ionic compounds: _____________ _________________________________________Examples of formulas and names of ionic compounds:

Illustration of ionic bonding

Dot Diagram of an ionic compound

Both types of compounds

-Use ___________________

____________________ in bond formation.

-Form bonds to complete_________________.

-Contain a _________________________.

-Formulas tell you__________________________

______________________________________.

-The name of the 2nd element ________________

_________________________________.

Substance Group C = Covalent Compounds-Contain _________________________________-Electrons are_________________between atoms-Bonds are _______________________________-Particles are______________________________.-__________________________________at room temperature.-Solids have a ________ melting point.-__________________________: solutions of this compound ______ conduct electricity.-Electronegativity difference is _______________ than 1.70 Paulings.-Can have single, ____________, or ___________ bonds.-When writing covalent formulas:_____________ _________________________________________-When naming covalent compounds: __________ _________________________________________Examples of formulas and names of covalent compounds:

Illustration of covalent bonding

Dot Diagram of a covalent compound

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Molecular Geometry: VSEPR ChartE = central atom X = noncentral atom : = lone pair of electrons Domain = a location of a bond or a lone pair of electrons Number of Domains

Arrangement of Domains (Shape Name)

General Molecular Formula

Molecular Shape(Actual Shape) Examples

2 Linear EX2 CO2

3 Equilateral triangular(three domains) EX3 BCl3, AlCl3

4 Tetrahedral(four domains) EX4 CH4, SiCl4

   Tetrahedral(four domains) EX3 NH3, PCl3

   Tetrahedral(four domains) EX2 H2O, SCl2

________________ ______________ ________________ _______________ ________________

COVALENT BONDING PRACTICE 1. How are covalent compounds formed?

2. Why don’t we look up charges for ions in a covalent compound?

3. What is the name of the particle type for covalent compounds?

For the following compounds,1) write the chemical formula 2) draw the compound’s Lewis Structure 3) determine the shape using VSEPR. Diatomic elements just go by their element names.

Chlorine 1)

2)

3)

Phosphorus trichloride 1)

2)

3)

Silicon tetrafluoride 1)

2)

3)Dihydrogen monoxide 1)

2)

3)

Carbon disulfide 1)

2)

3)

Nitrogen trihydride 1)

2)

3)Boron trifluoride 1)

2)

Carbon tetrachloride 1)

2)

Sulfur dichloride 1)

2)

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3) 3) 3)

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