1. Bonding Between Atoms

2. Why Do Atoms Form Bonds To get a stable octet of valence electrons.
Called a “noble gas configuration”

3. Changes in Energy Energy is released when bonds form.
Exothermic
Lower energy = more stable
Exothermic = Bond Forms
Endothermic = Bond Breaks

4. Bond Formation is EXOTHERMIC

5. Major Types of Bonds

6. IONIC BOND
Metal and Nonmetal
valence e- transferred

7. COVALENT BOND
All nonmetals
valence e- shared

8. Metallic Bonding Pure metals & alloys Valence electrons
become “mobile”
between all the atoms.

9. What Type of Bonding? _________CaCl2 _________C6H12O6 _________ CO2
_________ Fe
_________ H2O
_________ Al(NO3)3
_________ Mg
_________ NH3

10. Lewis Dot Diagrams of Atoms
Show valence electrons involved in bonding

11. Lewis Dot Diagrams of Ions
Positive Ions (cations): lose outer shell valence to get stable octet.
Negative Ions (anions): gain electrons to complete outer shell octet.
Do Bonding Packet Pgs 4, 5, 6

12. Crash Course: https://www.youtube.com/watch?v=QXT4OVM4vXI
Ionic Bonding
Crash Course:

13. Ionic Bonding Happens between metals and nonmetals
What are Ionic Bonds? (1:30)

14. Electronegativity Difference
Ionic compounds: large differences in atomic EN values ( > 1.7)
Greater EN diff. = more “Ionic Character”.

15. Ex: EN Values Metal Na = 0.9 Nonmetal Cl = 3.2
Nonmetal with higher EN “takes” electron(s) from metal

16. Atoms Become Ions Metals Lose Electrons:
Ex: Mg is 2-8-2
Loses 2 electrons to become Mg+2 2-8
Nonmetals Gain Electrons: usually take top (-) charge
become (–) ion
Ex: Cl is 2-8-7
Gains 1 electron to become Cl

17. Ionic Bond = Electron Transfer
As ions form, an exchange or transfer of electrons happens.
Lithium (metal) 2-1
Fluorine (nonmetal)

18. Positively and negatively charged ions form and attract each other due to OPPOSITE CHARGES.
IONIC BOND
Forming Table Salt :6 minutes -
ion
+ ion

20. They transfer enough electrons so that all get a stable octet of valence!

21. Drawing Lewis Dot Diagrams of Ionic Compounds

22. Ionic compounds have uniform crystalline lattice structure.

23. Can you identify an ionic compound from a covalent?
Ionic = Metal with nonmetals
_____________MgBr2
_____________Ca(NO3)2
_____________P2O5
_____________SiO2
_____________Na2S
_____________H2S

24. Ionic Compounds are Neutral
“Subscripts” show
ratio of ions
Total positive and
negative charges
must balance
Compound is
electrically neutral.

25. Writing Neutral Ionic Formulas
Write symbols of elements with charge
Criss-Cross charges if necessary to balance the formula
Put parenthesis around polyatomic ions if more than one in formula
Simplify if needed.
Tutorial on writing ionic formulas 9 min

26. Stock System for Naming Ionic Compounds
Binary:
Contain ions of 2 elements
Ex: MgCl2, Al2O3, NaCl

27. Name nonmetal with “-ide” ending.
Naming Binary Ionics
Name metal
Name nonmetal with “-ide” ending.
Note: Name never indicates # of ions
Ex: NaCl, MgBr2, CaO, Al2S3
Writing Ionic Formulas: (3:22)

28. Ternary Ionics: Contain 3 elements
Polyatomic ion present.
Note: Elements inside the polyatomic ion are covalently bonded (all nonmetals).
These compounds contain both ionic and covalent bonds!!
MgSO4

29. Naming Ternary Ionics (with polyatomic) Name Metal Name polyatomic ion
If two polyatomics, name them both
Ex: NaNO3, Ca3(PO4)2, NH4Cl
Ionics with Polyatomic Ions: (3:46)

31. Why does the 3rd compound use a Roman Numeral in it’s name?

32. When to Use a Roman Numeral
Roman numerals are used when the metal can have more than one possible charge.
Roman numeral indicates the charge the metal takes in that compound and must be indicated in the name
Ex: NiBr2 Nickel II Bromide
NiBr3 Nickel III Bromide

33. Name the following ionic compounds:
Fe(NO3)3 ____________________
NaF _________________________
Cu3P ________________________
Al2(SO4)3 ____________________

34. Write the correct formula for:
_____________cobalt III oxide
_____________magnesium sulfide
_____________ lead II nitrate
_____________ calcium phosphate

35. Properties of Ionic Compounds

36. High Melting Point Attraction between ions is very strong.
Requires large amount of
heat energy to separate
ions and make solid melt.
Higher MP than covalents

37. Solubility in Water
Most ionics will dissolve in water, or be “soluble”.
When dissolved in water they are “aqueous”
Ex: NaCl (aq)

38. Water is a “polar molecule”.
Acts like magnet to pull ions apart and into solution.
Ions are now “dissociated” or “hydrated” ions.

39. Conductivity
Ionic compounds conduct when ions are “mobile” or free to move about.
Ionic compounds conduct when:
Molten (melted or liquid) (l)
Aqueous (aq)

40. Molten Ionics can Conduct!

41. Conductivity DO NOT conduct when solid as the ions locked in place.
Most covalents do not conduct

42. Which compound has the highest Melting point?
KCl or SO2
Which substances conduct electricity?
NaCl (s)
CO2 (g)
MgBr2 (l)
C6H12O6 (s)
LiNO3 (aq)

43. Lattice Energy (Honors)
Energy released when ionic bond is formed
The more energy, the more stable and stronger the bond.
Related to Coulombic Attraction
Variables that Determine its Magnitude:
Atomic Size
Ion Charge
See Honors Packet Pages

44. Crash Course Chemistry: Nomenclature
(only watch first 6 minutes, skip section on naming acids for now)
Dancing Queen: Song about Ionic vs Covalent Bonding
Crash Course: Atomic Hookups