1. Ionic Bonding Notes

2. These are also called salts or crystals.
Ionic Bonds
ALWAYS formed between metals and non-metals Transfers electrons to become stable Results from the attractive forces between + and – ions. STRONGEST force BETWEEN elements [METALS ]+ [NON-METALS ]-
Lost e-
Gained e-
These are also called salts or crystals.

3. Formation of an Ionic Bond
When an atom loses or gives a valence electron to another atom, it becomes a (+) ion. This is a CATION.
When an atom takes or gains a valence electron from another atom, it becomes a (-) ion. This is an ANION.

4. Model of Ionic Bonding 1 valence e- 7 valence e- 8 valence e-
Cation – Na +1
Anion – Cl -1
1 valence e-
7 valence e-

6. Ionic Bond

7. Writing Formulas for Binary Ionic Compounds
To write a formula for a binary ionic compound
Write the ions that are named in the compound showing their charges.
In the formula, list the positive (cation) symbol first and then the negative (anion) symbol
Make sure the formula has the lowest whole number ratio.
Note: you never write subscript of 1; 1’s are always understood.
One easy way to figure out the formula of an ionic compound is to switch the oxidation number of each ion and use them as the subscripts (without the charge).
We call this Drop and Swap
DROP +/- signs and SWAP the superscripts to subscripts

8. Lewis Dot Structure 2+ 1- DROP AND SWITCH THE CHARGES
Shows the # of valence elecrons the atom has 2+ 1-
What is the charge on Ca?
What is the charge on F?
How many atoms of Ca and F are needed?
DROP AND SWITCH THE CHARGES

9. Lewis Dot Structure
Ca F-
Drop
Ca F1
Switch
Don’t write 1!!!
CaF2

10. Lewis Dot Structure Na and N[ [ -3 +1 [ [ 1+ 3-
Drop
Na N3
Switch +1 [ +1 [ -3 [
Na3N [ [ [ [ [ +1
Don’t write 1!!!

11. Exampl Ca+2 F-1 CaF2 Na+1 N-3 NaN3
Ex 1: Calcium and Flourine Ex 2: Sodium and Nitrogen
________________________________________________ ________________________________________________
Ca+2
F-1
CaF2
Na+1
N-3
NaN3

12. The formula must be in the lowest whole number ratio.
Ex 3: Write the formula for magnesium and sulfur. ________________________
Ex 4: Write the formula for aluminum and oxygen. ________________________
Mg+2
S-2
Mg2S2
MgS
Al+3
O-2
Al2O3

13. Naming Binary Ionic Compounds; Nomenclature
Ionic Compounds are made of a positive ion metal and a negative ion non-metal.
Write the name of the metal (cation) first
Write the root name of the nonmetal
Add “ide” to the root name of the nonmetal
Like this:
[Na]+ Sodium [Cl]- Chlorine
NaCl Sodium Chloride

14. Ex 1: Magnesium sulfide ZnBr3 zinc bromide K3N potassium nitride
Name: MgS _______________________________________
Magnesium sulfide
Practice
ZnBr3 zinc bromide
K3N potassium nitride
CaO calcium oxide
AlF3 aluminum fluoride