1. Chapter 7: Ionic and Metallic Bonding

2. Section 7.1: Ions

3. Valence Electrons
Electrons that are in the highest occupied energy level of an atom.
Mostly determine the chemical properties of an element
Valence electrons are usually the only electrons involved in a chemical bond.

4. How many valence electrons?
Look at the family (or column) it is in on the Periodic Table.
Family 1 has 1 electron
Family 2 has 2 electrons…etc. 1 8 H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ga Ge As Se Br Kr Rb Sr In Sn Sb Te I Xe Cs Ba Tl Pb Bi Po At Rn
or 2 2 3 4 5 6 7 Na

5. Electron Dot Structure (a.k.a. Lewis Dot Diagram)
How do you draw Electron Dot Structures?
Write the element symbol.
Determine what family it is in. Na
Then…put dots around the symbol to represent the valence electrons. Na

6. Practice these: B Ne

7. The Octet Rule
Atoms tend to gain or lose electrons to achieve the electron configuration of a noble gas (8 e-)
Noble gas configuration is 8 electrons in its highest orbital:
ns2np6
Exception is H and He: only 2 electrons to fill highest orbital

8. Cation Cations Definition: A positively charged ion.
Has a + sign in word.
Cation is an atom that has LOST electrons.
Naming:
element name (NO change)
Add word “ion”

9. Examples of Cations Li+1 Lithium ion Na+1 Sodium ion Mg+2
Magnesium ion

10. Anion Anions Definition: A negatively charged ion.
Letter “A” has negative sign
Anion is an atom that has GAINED electrons.
Naming:
Change end of element to ”-ide”
Add word “ion”

11. Examples of Anions
Br-1
Bromide ion
O-2
Oxide ion
Cl-1
Chloride ion

12. Section 7.2: Ionic Bonds and Ionic Compounds

13. Review… Magnesium # of valence electrons2
Gain or lose to achieve octet?
lose 2
Most stable ion formed:
Mg+2
Cation or Anion?
Positive, so it’s a cation

14. Ionic Compounds:
Compounds made up of metal cation and nonmetal anions.

15. Ionic Bonds
The electrostatic force that holds ions together.
Positive cations and negative anions attract each other.

16. Chemical formula: Li2O NaCl H2SO4
Shows the number and kinds of elements in a compound.
Always written with symbols and subscripts.
For example:
Li2O
NaCl
H2SO4

17. Electron Dot Structure and Ionic Bonds
Sodium and Iodine

18. Naming Ionic Compounds
3 rules:
Name of cation stays the same.
Change the end of the anion to “-ide”
If there is a polyatomic ion, the name doesn’t change. (see chart on page 192)

19. Electron Dot Structure and Ionic Bonds
Magnesium and Sulfur

20. Electron Dot Structure and Ionic Bonds
Potassium and Phosphorus

21. Electron Dot Structure and Ionic Bonds
Aluminum and Oxygen

22. Properties of Ionic Compounds
Crystalline solids at room temperature.
Generally have a high melting point (the elements are highly attracted to each other so they are hard to separate).
They conduct an electric current when melted or dissolved.