1. An Elemental Love Story
Ionic Bonding Part I
An Elemental Love Story

2. Demo Burning string demo
Clean string vs Sugar soaked string vs Salt soaked string
Any difference?

4. 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.

5. Before we dive in What is a chemical bond?
What are three main different types of bonds?
Why do elements form ions?
What is a cation?
What is an anion?

6. Bonds 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.

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

8. Metallic Bonding
Strong forces of attraction are responsible for the high melting point of most metals.

9. 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

10. Properties of Metals
Metals are good conductors of heat and electricity
Metals are malleable
Metals are ductile
Metals have high tensile strength
Metals have luster

11. Metal Alloys
Alloys: some metal atoms replaced by others of similar size.

12. Ionic bonding
Ionic compounds bond in repeating 3-dimensional patterns with alternating positive and negative ions
called crystal lattice.

13. Ionic Crystal Lattice Shapes

14. Ionic bonding All salts are ionic compounds and form crystals.
NaCl forms the simplest cubic structure

15. 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

16. Properties of Ionic Compounds
Lab!
We will be examining the properties of ionic compounds next double with a lab.
In the meantime, we will move onto how and why ions bond.

17. Great BBC video on ions

18. Know our ions inside and out
In order to be successful with ionic bonding, you need to know what ion each element in the s and p block will form.
Practice on the Ion worksheet grid in the packet

19. The Octet Rule – Ionic Compounds
Ionic compounds form so that each atom, by gaining or losing electrons, has an octet of electrons in its highest occupied energy level.
Ionic bonds form between metals and nonmetals!
Metals lose electrons to form positively-charged cations
Nonmetals gains electrons to form negatively-charged anions

20. 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

21. Ionic Bonding

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

23. 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

24. Writing Ionic Compounds with Electron Dot Diagrams

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

26. Drawing Ionic Compounds
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

27. Drawing Ionic Compounds
How would these elements bond?
Mg Br

28. Draw the ionic compounds
How about
K S

29. 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

30. 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

31. 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

32. 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?

33. 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

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

35. 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

36. Practice!
Let’s try writing our predicting ion charges and and writing ionic compounds using the criss cross method

37. Ionic Bonding Wrinkles
Polyatomic molecules and
METALS WITH MULTIPLE IONS

38. 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

39. Polyatomic ions
You will not be asked to memorize the polyatomic ions, but…
You do need to be able to recognize them
And use a resource to determine its ionic charge
So that you can balance and write ionic compounds!

40. Polyatomic Ion Names CO3 2- carbonate OH – hydroxide SO4 2- sulfate
PO4 3- phosphate
NO3– nitrate
ClO3– chlorate
NH4 + ammonium

42. 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

43. ( ) 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

44. 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.

45. METALS WITH MULTIPLE IONS
Up until now, we’ve only been working with ions from the s and p block and ignoring d-block
This is because d-block metals as well as other metals can often form more than one type of ion
Again, you will not have to memorize these ions, but be able to use a resource to write ionic compounds with them.

46. 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

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

50. Practice!
Now, let’s practice writing ionic compounds with either polyatomic ions or METALS WITH MULTIPLE IONS