October 4*5*1/1/1*1, 2009

Objectives• SWBAT show the formation of ionic bonds• SWBAT make create balanced ionic compounds• SWBAT Track tests

Catalyst• How many electrons will the following atoms need to

gain or lose to be stable??– Na– Cl– Pb– Xe– Ca

Agenda

• Catalyst Review• Tracking • Formation of Ionic Compounds!

Unit 3 CHAMPIONS!! (90% and above)

Period 2 (79% Avg)• DiQuan Forcell• Ruben Garcia• Dalvin Hickerson• Iesha Nelson• Jahaira Sanchez• Brandon Toney

Period 3 (80% Avg)• Jasmine Castro• Jonathan Cordero• Christina DeArmas• Taylor Delaune• Kaynetra Hunter• Angelle Johnson• Harpreet Kaur• Jontrel Mackey• Kevin Martin• Isaac Wallis• Steven Webb

Ionic Bonds!

Formation of an ion

• How many electrons do the following atoms gain or lose to become stable?– Na – Cl– We have a new method of writing this:

• We call it showing the formation of an ion

• What is different about how we write each one?

Lose 1e-

Gain 1e-

Na Na+ + 1e-Cl + 1e- Cl-

Losing electrons

Gaining electrons

Formation of ion practice

• Show the formation of the following ions:• First figure out if it will gain or lose e-• Then show the formation of the ion

– H– B– Mg– O– I

Ionic BONDS•Forms between metal and

non-metal•Forms between a cation

and anion

Ionic BONDS!

• When an ionic bond forms, we need to balance out the oxidation numbers (charges) to equal ZERO.

• In other words, the same number of electrons need to be gained or lost overall

Ionic BONDS!

• If we wanted to form an ionic bond between Sodium and Chlorine…

1. Show the formation of the stable ions– Na Na+ + 1e-– Cl + 1e- Cl-

2. Make sure the same number of electrons have been transferred, if not then multiply to make them the same

3. Write out your final expression showing the number of each atom

Na+ + Cl- NaCl

Let’s try another one!

• Show what ionic compound will form from Potassium and Sulfur.1. Show the formation of the stable ions

2. Make sure the same number of electrons have been transferred, if not multiply to make them the same.

3. Write out your final expression

The hardest example you’ll see…

• Show what ionic compound will form from Aluminum and Oxygen

Try these on your own

• Show what ionic compounds will form:– Aluminum and Oxygen– Rubidium and Iodine– Magnesium and Oxygen– Strontium and Nitrogen

Alright…

• That process takes a long time…scientists aren’t going to do it every single time.

• WE HAVE A SHORCUT TO FIND WHAT IONIC COMPOUND WILL FORM!

• Get ready for it…

Kris Kross Method!

Ca3As2

Ca2+As3-

Write down the stable ions and cross the oxidation

numbers (charges) to make them subscripts

Na1+Cl1- NaCl

Pb4+O2- Pb2O4

Ionic Compounds

K F Ba N

Ga O Ca Cl

K Si Group 1 2 3 4 5 6 7 8Charge 1

+2+

3+

4-

3-

2-

1-0

Ionic Compounds

K+F- Ba N

Ga O Ca Cl

K Si Group 1 2 3 4 5 6 7 8Charge 1

+2+

3+

4-

3-

2-

1-0

Ionic Compounds

KF Ba N

Ga O Ca Cl

K Si Group 1 2 3 4 5 6 7 8Charge 1

+2+

3+

4-

3-

2-

1-0

Ionic Compounds

KF Ba2+N3-

Ga O Ca Cl

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-0

Ionic Compounds

KF Ba3N2

Ga O Ca Cl

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-0

Ionic Compounds

KF Ba3N2

Ga3+O2- Ca Cl

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-0

Ionic Compounds

KF Ba3N2

Ga2O3 Ca Cl

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-0

Ionic Compounds

KF Ba3N2

Ga2O3 Ca2+Cl-

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-0

Ionic compounds

KF Ba3N2

Ga2O3 CaCl2

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-0

Ionic compounds

KF Ba3N2

Ga2O3 CaCl2

K+Si4-Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-0

Balancing Chemical Reactions

KF Ba3N2

Ga2O3 CaCl2

K4Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-0

For Polyatomics it gets a bit more

complexPb4+SO4

3- Pb3(SO4)4

(NH4)1+PO43- (NH4)3 PO4

Practice with writing formulas for ionic

compounds

Group 1 2 3 4 5 6 7 8Charge 1+ 2+ 3+ 4- 3- 2- 1- 0

Exit Ticket

1. What do the two charges in an ionic compound have to balance to?

2. Write the formulas for the following ions:

A) K O

B) Na Br

C) Mg S