bonding- what does bonding mean? what is a chemical bond? a chemical bond results when electrons are...

BONDING-

What does bonding mean?

What is a chemical bond?

• A chemical bond results when electrons are gained, lost, or shared between atoms

• bonds form so atoms can have 8 valence electrons

Types of BONDS• If electrons are gained or lost (transferred), an IONIC BOND results• If electrons are shared, a COVALENT BOND results

– TIP to remember the difference between the two (co and I) – $ example

How does bonding affect the type of compound formed?

• The type of compound that is formed depends on the bond between the two elements.

COMPOUNDS- combination of at least two elements

• There are two types of compounds–Ionic compounds

–Molecular (covalent) compounds

• Windows media player animation – ionic bonding/ covalent boding animation

Types of Compounds Continued

• Covalent bonds form between NONMETALS only

• Example: CO2, SO2

• Covalent bonds form molecular compounds

"My name is Bond -

Covalent Bond."

Types of Compounds Continued

• Ionic bonds form between METALS & NONMETALS only

• Example: NaCl, MgCl2

• Ionic bonds form ionic compounds

Classify the following as Covalent or Ionic Compounds

• 1. Li3N

• 2. P2O5

• 3. CO

• 4. MgS

• 5. FeCl3

Which of the following compounds is ionic?

  A. HCl   B. H2O

  C. NaCl   D. CH4

• 1. CO2

• 2. CCl4• 3. MgS

• 4. AlF3

• 5. HCl

Which are ionic compounds?

• We are going to spend the next few days exploring ionic compounds before we talk any more about molecular compounds.

• In order for ionic bonds to form, the atoms that are combining must first become ions!

• IONIC COMPOUNDS are formed from IONS

Atoms and Ions

• Ions are different from atoms because:

• Ions are charged particles

• Ions are atoms that have lost or gained e-

Why Atoms Change

• Atoms are electrically neutral (#p+ = #e-)

• However, atoms have a mission It is to become like a noble gas

Octet Rule

• The Octet Rule states that all atoms want to achieve a noble gas configuration (have 8 valence electrons) in order to become chemically stable

• Atoms accomplish this through gaining, losing, and sharing of electrons

Ions

• An atom which loses electrons becomes positively charged and is called a cation

• Metals form cations–Ex. Mg+2

• Smart board atom example

Ions

• An atom which gains electrons becomes negatively charged and is referred as an anion

• Nonmetals form anions

Write Symbols for the following:

• 1. A sulfur atom that gains 2 e-

• 2. A sodium atom that loses 1 e-

• 3. A nitrogen atom that gains 3 e-

• 4. A magnesium atom that loses 2 e-

• Identify the anions and cations above• Determine how many protons and

electrons each atom has

• Smart board atom example Ion 1:48 video clip

• http://streaming.discoveryeducation.com/clickDirector.cfm/type/video/action/stream/guidAssetID/ae2c7a14-611a-4857-86f2-66933e4c286a

Complete the following• Symbol Mass # Atomic # #p+ #n0 #e-

• Ag 108

• Ca2+ 29

• 65 30 30

• 1 2 0

• 59 28 26

Two atoms are walking down the street one day, and one of them says to the other:"Hey, wait up a second.  I

think I lost an electron"The first atom replied, "Are

you sure?"The second atom exclaimed,

"Yes, I'm positive!"

Ionic Charges of Elements• The following families take the following

charges in IONIC COMPOUNDS:• Group 1: +1• Group 2: +2• Group 3A: +3• Group 4A: 4

Ionic Charges of Elements• Group 5A: -3• Group 6A: -2• Group 7A: -1• Group 8A: 0 *do NOT form

compounds• Groups 3-12 can have different

charges

Determine the charge the following elements would have when they formed ions.

• 1. Na

• 2. Cl

• 3. S

• 4. P

• 5. Ra

• 6. Ca

• 7. I

• 8. Sr

• 9. Al

• 10. O

• ION CLASS ACTIVITY… find your two matches!

Review!• 1. Which of the following are ionic compounds:

• H2O, NaOH, Rb2O, CO2

• 2. What charges would the following have if they became an ion?

• a. Na b. F c. Ca d. Ga e. Ne

• 3. Classify the elements in #2 as metal, nonmetal or metalloids

Chemical Formulas• Chemical Formulas show the

kinds and number of each atom present in a compound

• The small numbers written below a symbol are called SUBSCRIPTS

• Subscripts show the number of each atom present

Determine the kinds and number of each atom in the following:

• 1. CO2

• 2. CCl4• 3. MgS

• 4. AlF3

• 5. HCl

Binary Ionic

Compounds

Binary Ionic Compounds• A binary ionic compound is an ionic

compound that contains only 2 elements

• Examples:

• NaCl CaF2

• Binary ionic compounds use the ionic charges in order to write correct formulas

Writing Correct Chemical Formulas for Binary Ionics:

• 1. Determine the charge of each ion

• 2. Crisscross the value associated with the charge to the other atom

• 3. Reduce the subscripts to the lowest possible terms

• 4. Check to make sure that the total charge of the formula adds up to zero

Example: Write the formula for:

• Magnesium and Chlorine

Mg Cl

MgCl2

-12+

Write Formulas for the following:

• 1. Mg, P

• 2. Al, S

• 3. K, I

• 4. Sr, O

• 5. Ba, Br

Naming Ionic Compounds

• 1) Name the metal first

• 2) Name the nonmetal, but change the ending of the nonmetal to “ide.”

Example

• 1. K3N–Potassium Nitride

Name the following compounds:

•1. MgCl2•2. Li2O

•3. BaS

Name the following compounds• 1. MgO

• 2. Rb3N2

• 3. Al2O3

• 4. KBr

• 5. Na2S

Write Formulas for the following given the names:

• 1. Calcium Chloride• 2. Cesium Oxide• 3. Sodium Fluoride• 4. Aluminum Sulfide• 5. Potassium Nitride

• QUICK GAME…

Name the following compounds

• Na2O

• BaBr2

Write Formulas for when the following elements combine:

• Al, Se

• Li, F

Name the following compounds

• AlN

• CuF

Write formulas for the following compounds:

• Lithium Chloride

• Sodium Oxide

Write formulas for the following compounds:

• Potassium Phosphide

• Strontium Sulfide

Write Formulas for when the following elements combine:

• Mg, N

• Al, Cl

Write the correct formula:

• Strontium Sulfide

• Write the correct formula:

• Potassium Bromide

• Barium Phosphide

• Write the correct formula for Copper Iodide. Copper loses two electrons.

• HW… binary compound worksheet.

Properties of Ionic Compounds

• Visit http://home.carolina.rr.com/bwhitson

• Learn about properties of ionic compounds (click on unit 8 & 9)

• Expected Outcomes:

• 1) describe formation of ionic bond

• 2) knowledge of properties of ionic bonds

• 3) knowledge of metallic bonds & alloys

KEY PROPERTIES OF IONIC COMPOUNDS• Most are crystalline solids at

room temperature

• High melting points

• Conduct an electric current when melted or dissolved in water.

• Time to “bond” with your classmates.

Polyatomic Ions

• Polyatomic Ions are composed of at least two atoms

• Poly = many ; atomic = atoms

• The atoms function as one unit but have a charge

Examples of Polyatomic Ions

See EOC reference table

•OH- Hydroxide Ion

•CO32- Carbonate Ion

•NH4+ Ammonium Ion

Ternary Compounds

Ternary Compounds• Ternary Ionic Compounds

contain at least 3 different elements

• A ternary compound always contains a polyatomic ion

Rules for naming ternary compounds

• 1. Name the metal.• 2. Name the polyatomic ion by

looking at the EOC reference table.

• Example: LiNO3

• Lithium Nitrate

Examples:

• Ca(OH)2

• Calcium Hydroxide

• MgCO3

• Magnesium Carbonate

Name the following:

• 1. MgSO4

• 2. Na2CO3

• 3. Ba(OH)2

• 4. (NH4)2SO4

• Are these compounds still considered to be ionic?

NAME THE FOLLOWING compounds. Some are binary, and some are ternary. Hold up your answer on the dry erase boards when you have an answer.

• 1. Na3N

• 2. Ag2CO3

• 3. NH4OH

• 4. Cu3PO4

• 5. SrO

• 6. Ba3P2

• 7. SrCO3

• 8. (NH4)Cl

• 9. Na2(SO4)

• 10. MgO

Ternary Compounds

• Writing formulas for ternary compounds is similar to binary ionic compounds

• Always write the polyatomic ion in parenthesis before crossing the charges

Example: Write the formula for:

• Magnesium Nitrate

Mg (NO3)

Mg(NO3)2

-12+

Write Formulas for the following

• 1. Magnesium Sulfate

• 2. Ammonium Chloride

Write formulas

Sodium Carbonate

Ammonium Phosphate

Write formulas

• Aluminum Phosphate

• Sodium Sulfide

• Name the following:

• Ba3P2

• ZnCO3

• Write formulas for:

• 1. Sodium oxide

• 2. Ammonium sulfide

Name the following

• (NH4)Cl

• Na3(PO4)

Write formulas

Potassium hydroxide

Barium Sulfate

Lithium Phosphate

Name the following

• MgO• Ag2CO3

• Name the following:

• Na3P

• NH4OH

• Cu3PO4

• FeO

• CUT AND PASTE TERNARY COMPOUND ACTIVITY!