1. You know the drill!

2. Octet Rule = atoms tend to gain, lose or share electrons so as to have 8 electrons (or a completed shell)

3. 4 3 2 C would like to gain electrons. N would like to gain electrons.
O would like to gain electrons.

4. Elements have different electron configurations.
Different electron configurations mean different levels of bonding.

5. Chemical bonds: an attempt to fill electron shells.
Lewis Dot Diagrams: Symbols of atoms with dots to represent the valence electrons.

6. Let’s practice!

8. IONIC BOND A bond formed between two ions by the TRANSFER of electrons
IONIC BOND A bond formed between two ions by the TRANSFER of electrons *bond between metals and nonmetals

10. Formation of Ions
Ionic compounds result when metals react with nonmetals
METALS LOSE electrons to match the number of valence electrons of their nearest noble gas
Positive ions (cations) form when the number of electrons are less than the number of protons
Example of metallic ionic charges: 1+, 2+, 3+

11. NONMETALS GAIN electrons from metals
Negative ions (anions) form when the number of electrons are more than the number of protons.
Example of nonmetal ionic charges: 3-, 2-, 1-

13. What did we learn? A. Number of valence electrons in aluminum
1) 1 e ) 2 e- 3) 3 e-
B. Change in aluminum electrons for octet
1) lose 3e ) gain 3 e ) gain 5 e-
C. Ionic charge of aluminum
1) ) ) 3+

14. Give the ionic charge for each of the following:
A. 12 p+ and 10 e-
1) 0 2) 2+ 3) 2-
B. 50p+ and 46 e-
1) 2+ 2) 4+ 3) 4-
C. 15 p+ and 18e-
2) ) 3- 3) 5-

15. COVALENT BOND A bond formed by the SHARING of electrons
COVALENT BOND A bond formed by the SHARING of electrons *bond between nonmetal and nonmetal

16. Nonpolar Covalent Bonds
When electrons are shared EQUALLY.
H2 or Cl2

17. Oxygen Atom
Oxygen Atom

18. When electrons are shared but shared UNEQUALLY.
Polar Covalent Bonds
When electrons are shared but shared UNEQUALLY.
H2O

19. Unevenly matched, but willing to share.
Polar Covalent Bonds:
Unevenly matched, but willing to share.

20. METALLIC BOND *bond found in metals
holds metal atoms together very strongly

21. Metallic Bonds: Mellow dogs with plenty of bones to go around.

22. What did we learn?