1. Part I – Ionic bonding An Elemental Love Story

2. Before we dive in What is a chemical bond?
What are three main different types of bonds?
What are some properties of these different types of bonds?

3. Bonding Q: How do elements combine to form compounds?
A: Compounds have different forces that hold groups of atoms together and make them function as a unit called bonds.

4. Bonding Bonds come in three main varieties:
Ionic bonds – transfer of electrons between metals and non metals
Metals & Metallic bonds – when metal cations bond they share a sea of delocalized electrons.
Covalent bonds – sharing of electrons between two nonmetals

5. Demo Let’s compare two of those types of bonds – ionic and covalent
Which do you think is stronger?
How might we tell which are stronger?
Burning string demo
Plain string vs sugar soaked string vs salt soaked string
Any difference?

6. Ions and Ionic Bonds
Clearly ionic bonding is very strong!

7. Ion Research Mission For this week, you will read articles about:
Iodine deficiency disorder
Pros and cons of fluoride
The importance of potassium
The dangers of chromium
After gathering information, your group will present what you learned and how it relates to ions and ionic bonding.

8. Great BBC video on ions

9. Ionic bonding Bonds that form between oppositely charged ions
Ionic bonds form between metals and nonmetals!
Metals become positive ions (cations) and nonmetals become negative ions (anions)
Opposites attract!
This attraction forms an Ionic bond and each then are left with a complete octet!

10. Properties of Ionic Compounds
Structure:
Crystalline solids
Melting point:
Generally high
Boiling Point:
Electrical Conductivity:
Excellent conductors, molten and aqueous
Solubility in water:
Generally soluble

11. Ionic Bonding: Sodium Chloride Example
Sodium has 1 valence electron
Chlorine has 7 valence electrons
An electron transferred gives
each an octet
Na: 1s22s22p63s1
Cl: 1s22s22p63s23p5

12. Ionic Bonding

13. Ionic Bonding: Sodium Chloride Example
This transfer forms ions, each with an octet:
Na+ 1s22s22p6
Cl- 1s22s22p63s23p6

14. Ionic Bonding: Sodium Chloride Example
The resulting ions come together due to electrostatic attraction
(opposites attract):
Na+
Cl-
The net charge on the compound must equal zero

15. Writing Ionic Compounds with Electron Dot Diagrams

16. Drawing Ionic compounds
How would these elements bond?
Li F K Br

17. Drawing Ionic Compounds
Unlike our atomic dating game…Not all relationships are 1:1 with sharing of valence electrons.
Sometimes you need more of one element than the other to make a neutral compound

18. Interactive – Ionic bonding
Write the ions formed and then the ionic compound formulas
Can you see a pattern?

19. Al3+ S2- Criss Cross method! 2 3 = Al2S3 Example: Aluminum sulfide
1. Write the formulas for cation and anion, including CHARGES!
2. Do charges balance?
3. If not, use criss-cross method to balance subscripts.
Al3+
S2- 2 3
Not balanced!
Now balanced.
= Al2S3

20. Be2+ Cl- Criss Cross Method! 2 = BeCl2 Example: Beryllium chloride
1. Write the formulas for cation and anion, including CHARGES!
Be2+
Cl- 2
Now balanced.
2. Do charges balance?
Not balanced!
3. Balance charges, if necessary, using subscripts. Use criss-cross method to balance subscripts.
= BeCl2

21. Mg Cl Na O Al S Try the criss cross method
Magnesium chloride: Magnesium loses two electrons and each chlorine gains one electron
Mg Cl
Sodium oxide: Each sodium loses one electron and the oxygen gains two electrons
Na O
Aluminum sulfide: Each aluminum loses two electrons (six total) and each sulfur gains two electrons (six total)
Al S

22. Naming Ionic Compounds
You may have noticed that the name of the nonmetal in the previous compounds sounded different (chloride instead of chlorine, oxygen inside of oxide)
Can you think of what might be a naming rule for ionic compounds?
What’s the order we use?
Do any of the names change?

23. Naming Ionic Compounds
Name the cation first and then the anion
Cations – use the name of the element
Anions – use the name of the nonmetal but change the ending to an –ide

24. Metal
Monatomic Cations
Ion name
Lithium
Li+
Sodium
Na+
Potassium K+
Magnesium
Mg2+
Calcium
Ca2+
Barium
Ba2+
Aluminum
Al3+

25. Nonmetal
Monatomic Anions
Ion Name
Fluorine F-
Fluoride
Chlorine
Cl-
Chloride
Bromine
Br-
Bromide
Iodine I-
Iodide
Oxygen
O2-
Oxide
Sulfur
S2-
Sulfide
Nitrogen
N3-
Nitride
Phosphorus
P3-
Phosphide

26. Try some on your own Cl - S 2- As 3- Li+ Li+ Cl - LiCl Mg 2+ Al 3+
Lithium chloride
Mg 2+
Al 3+

27. Ionic Bonding Wrinkles
Polyatomic molecules

28. Polyatomic ions
Many ionic compounds contain polyatomic ions which are ions made up of more than one atom.
Polyatomic ions are atoms that are covalently bonded together and act as an individual ion.
Because it exists as a unit, DO NOT change the subscripts within the ion.
In Ionic Compounds, you put ( ) around them

29. Polyatomic ions
You will find it useful to remember a few polyatomic ions that we use repeatedly
So that you can balance and write ionic compounds!
Tyler Dewitt (5:15)

30. Polyatomic Ion Names NH4 + ammonium -1 -2 -3 OH – hydroxide
NO3– nitrate
CN – cyanide
CO3 2- carbonate
SO sulfate
PO4 3- phosphate

31. Writing Ionic Compound with polyatomics
Example: Zinc hydroxide
1. Write the formulas for cation and anion, including CHARGES!
( )
Zn2+
OH- 2
Now balanced.
2. Do charges balance?
Not balanced!
3. Balance charges , if necessary, using subscripts. Use () if more than one polyatomic ion. Use criss-cross method to balance subscripts.
= Zn(OH)2

32. ( ) Ba2+ NO3- 2 = Ba(NO3)2 Example: Barium nitrate
1. Write the formulas for cation and anion, including CHARGES!
( )
Ba2+
NO3-
2. Do charges balance? 2
3. Balance charges , if necessary, using subscripts. Use () if more than one polyatomic ion. Use criss-cross method to balance subscripts.
Now balanced.
Not balanced!
= Ba(NO3)2

33. Writing Ionic Compound with polyatomic molecules
Example: Ammonium sulfate (note the 2 word name)
( )
NH4+
SO42-
1. Write the formulas for cation and anion, including CHARGES! 2
Now balanced.
2. Do charges balance?
Not balanced!
= (NH4)2SO4
3. Balance charges , if necessary, using subscripts. Use () if more than one polyatomic ion. Use criss-cross method to balance subscripts.

34. Try some on your own CO3 2- OH - SO4 2- PO4 3- Na+ Na+ (CO3) 2-
Sodium carbonate
NH4 +
Ca 2+
Ca 2+ (CO3) 2-
Ca(CO3)
Calcium carbonate
Al 3+

35. Ionic Bonding Wrinkles
TIME TO TALK ABOUT THOSE TRANSITION D BLOCK METALS WE’VE BEEN AVOIDING!

36. Metallic Bonding
The chemical bonding that results from the attraction between metal cations and the surrounding sea of electrons
Vacant p and d orbitals in metal's outer energy levels overlap, and allow outer electrons to move freely throughout the metal
Valence electrons do not belong to any one atom

37. Properties of Transition Metals
Metals have high melting points.
Metals are good conductors of heat and electricity
Metals are malleable
Metals are ductile
Metals are strong
Metals have luster

38. ELECTRONS IN TRANSITION METALS
Up until now we have only talked about ions from the s and p block.
This is because transition metals can be tricky.
Since d-orbital electrons are held less tightly than s and p orbitals,
Almost all transition metals can become ions with multiple charges.

39. METALS WITH MULTIPLE IONS
For those metals it is important to represent which ion it is with a roman numeral.
If it is +1 you put a (I) after the name of the metal
If it is +2 it is a (II) after the name of the metal
If it is a +3, you put a (III) after the name of the metal
You include this roman numeral in the name ONLY for metals that form multiple ions!
For example: NiBr2 would be Nickel (II) Bromide

40. Roman numeral review! VI II
III IV
VII I V

41. Look at your periodic table
Only three transition metals have a constant charge. It will be handy for you to remember those since you should NOT use a roman numeral for those!
Zinc +2
Silver +1
Cadmium

42. Let’s try some Br - O2- P 3- CO3 2- Pb+2 Pb+2 (CO3) 2- Pb(CO3)
Lead (II) carbonate
Cu +
Zn 2+
Zn 2+ (CO3) 2-
Zn(CO3)
Zinc carbonate
Co 3+

43. Practice!
Now, let’s practice pull it all together