1. Chemical Bonding

2. Why do Bonds Form? Atoms want to have full outer shells
When atoms bond, each atom has a full energy level of valence electrons (just like the noble gases)

3. Types of Bonds
Two main types of bonding
Ionic
Covalent

4. What are some things you remember about chemical bonding?

5. Ionic bonding
Which group(s) do you think will lose electrons? Will this make them positive or negative?
Which group(s) do you think will gain electrons? Will this make them positive or negative?

6. Ionic Bonds
Atoms of metals tend to lose electrons to form positive ions (cations)
Nonmetals tend to gain electrons and form negative ions (anions)
Ionic bonds form when one atom gives electron(s) to another atom

7. Characteristics of Ionic Compounds
Conduct electricity when melted or dissolved in water
High melting and boiling points
Strongest bonds!

8. Oxidation Numbers
The oxidation number is equal to the charge of an atom after it has gained or lost electron(s)
Ex: NaCl

9. Practice Calcium + Oxygen Magnesium + Chlorine Aluminum + Sulfur
Ag+2 + Cl
Draw Lewis dot structure
Oxidation numbers
Show electron transfer
Write the formula

10. Element Speed Dating 1. Name 2. “Profile Picture” (Lewis Dot Model)
3. What do you have to bring to a stable relationship? (Number of valence electrons)
Directions:
In each rotation,
Write the name of your element partner.
If you can form a bond, identify it as ionic or covalent and write the resulting formula. If not, write “no bond.”
4. What do you want out of a relationship? (Will you lose or gain electrons? How many?)

11. Use the electronegativity values listed below to answer the following questions.
Element X = 3.44
Element Y = 0
Element Z = 0.82
Which element is most likely a metal?
Which elements are nonmetals?
Which two elements would likely be able to form an ionic bond?
In the ionic bond, identify the cation and the anion.

12. Before You Leave… What is one thing you learned today?
What is one question you still have?
What is one thing you already know (or can predict) about covalent bonding?

13. Covalent Bonds Formed by atoms sharing electrons
Usually formed between nonmetals
Weaker than ionic bonds

14. Characteristics of Covalent Bonds
Low melting and boiling points
Do not conduct electricity
Can be solid, liquid, or gas
Can share more than one pair of electrons
Double or triple bond

15. Covalent Practice Chlorine and Chlorine Hydrogen and Oxygen
Oxygen and Oxygen
Carbon and Selenium
Nitrogen and Sulfur

16. Ionic or Covalent? PH3 LiCl A diatomic molecule
Compound A melts at a lower temperature than Compound B.
Compound X does not conduct electricity.