1. Drill Quiz: Define the law of conservation of mass.
Determine the limited reactant in the following:
4Al + 3O Al2O3
10g of Al and 10g of Oxygen gas were used to produce Al2O3.

2. Objective:
SWBAT:
Distinguish between cations and anions in order to model ionic bonding by combining Lewis Dot diagrams.

3. SAT Enrichment: C3H8 + 5O2 3CO2 + 4H2O
If the number of moles of O2 is given in a problem, and the number of CO2 is desired, the appropriate mole ratio to use is….
1 mole C3H8 / 3 moles CO2
3 moles CO2 / 5 moles O2
4 moles H2O / 5 moles O2
5 moles O2 / 3 moles CO2
5 moles O2 / 4 moles H2O

4. Webquest 30 min Complete the WebQuest using the computers.
30 min

5. Chemical Bonding
Chemical bonding: the connection of two or more atoms based on the attraction between positive nuclei and negative electrons

6. Why bond?
To have a full valence shell (like the nobel gases) of electrons
What constitutes a full valence shell?
Octet (8) rule
Exceptions
Hydrogen: 2 electrons total
Beryllium: 4 electrons total
Boron: 6 electrons total

7. Important Terms
Ionic bonding: the formation of chemical bonds between ions that have gained or lost electrons to achieve a full valence shell
Ionic bonds typically form between a metal and a nonmetal

8. More Important Terms
Ion: an atom that has become charged by gaining or losing electrons
Cation (kat-eye-on): a positive ion
Cations have lost electrons
Anion (an-eye-on): a negative ion
Anions have gained electrons
Polyatomic Ion: an ion including more than one atom
Polyatomic ions can replace either a metal or a nonmetal in an ionic compound

9. How do ionic bonds form? Metals and nonmetals are ionized
Electrons are transferred from the metals to the nonmetals
The metals become positive (cations)
The nonmetals become negative (anions)
The ionic bond is formed by the attraction of the positive cation to the negative anion

10. Ionic Bonding Na + → → Cl Na+ + Cl- NaCl Example: Sodium plus chlorine• • • • Na + • • → • • → • Cl
Na+ +
Cl-
NaCl • • • • • • •

11. How can you predict what an ion’s charge will be?
The representative groups on the Periodic Table can show how many electrons elements will gain or lose 1+ 2+ 3+ 4± 3- 2- 1- 1 H
Hydrogen 3 Li
Lithium 11 Na
Sodium 19 K
Potassium 37 Rb
Rubidium 55 Cs
Cesium 87 Fr
Francium 4 Be
Beryllium 12 Mg
Magnesium 20 Ca
Calcium 38 Sr
Strontium 56 Ba
Barium 88 Ra
Radium 5 B
Boron 13 Al
Aluminum 31 Ga
Gallium 49 In
Indium 81 Tl
Thallium 6 C
Carbon 14 Si
Silicon 32 Ge
Germanium 50 Sn
Tin 82 Pb
Lead 7 N
Nitrogen 15 P
Phosphorus 33 As
Arsenic 51 Sb
Antimony 83 Bi
Bismuth 8 O
Oxygen 16 S
Sulfur 34 Se
Selenium 52 Te
Tellurium 84 Po
Polonium 9 F
Fluorine 17 Cl
Chlorine 35 Br
Bromine 53 I
Iodine 85 At
Astatine 2 He
Helium 10 Ne
Neon 18 Ar
Argon 36 Kr
Krypton 54 Xe
Xenon 86 Rn
Radon
Group 2: Alkaline Earth Metals
Lose 2 Electrons
Charge: 2+
Group 4
Gain or lose 4 Electrons
Charge: 4±
Group 1: Alkali Metals
Lose 1 Electron
Charge: 1+
Group 8: Noble Gases
Full Valence Shell
Charge: 0
Group 7: Halogens
Gain 1 Electrons
Charge: 1-
Group 6: Chalcogens
Gain 2 Electrons
Charge: 2-
Group 5
Gain 3 Electrons
Charge: 3-
Group 3
Lose 3 Electrons
Charge: 3+

12. Properties of Ionic Compounds
Strong bond
Dissociation
Large electronegativity difference

13. Electronegativities Electronegativities for the first six periods
The difference between two elements’ electronegativities indicates the degree of electron sharing (or transfer) in a chemical bond
As electronegativity difference increases, degree of sharing decreases H
2.1 Li
1.0 Be
1.5 B
2.0 C
2.5 N
3.0 O
3.5 F
4.0 Na
0.9 Mg
1.2 Al Si
1.8 P S Cl K
0.8 Ca Sc
1.3 Ti V
1.6 Cr Mn Fe Co
1.9 Ni Cu Zn Ga Ge As Se
2.4 Br
2.8 Rb Sr Y Zr
1.4 Nb Mo Tc Ru
2.2 Rh Pd Ag Cd
1.7 In Sn Sb Te I Cs
0.7 Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At

14. Predicting Bond Type An electronegativity difference of
≥ 1.7 results in an ionic bond
Example: KBr
EN of K = 0.8
EN of Br = 2.8
2.8 – 0.8 = 2.0
2.0 is greater than or equal to 1.7, so the bond is ionic.

15. Example
MgO
Mg: O: 3.5
3.5 – 1.2 = 2.3
Ionic

16. Example
H2O
H: O: 3.5
=1.4
Not ionic

17. Extension:
Thermite Reaction Video:
10 min

18. Summary Did we accomplish the objective? Explain.
Identify the difference b/w cations and anions.
What criteria would you use to assess the bonding of a compound?
Construct a method you can use to determine the formation of a compound using Lewis dot diagrams.

19. Exit Ticket/Homework
Ionic Bonding Exit ticket:
Homework NONE!
5 min