1. Ionic Bonding

2. New Unit: Chemical Bonding
Essential Questions: What are the processes by which different atoms come together to form new compounds and what forces hold solutions of these compounds/molecules together?

3. Ions An atom with a charge Positive: cation Negative: anion
How do these atoms become charged?

4. Valence Electrons Electrons in the highest occupied energy level
The number of valence electrons greatly determines chemical properties of an element and how it will react
How can we find the number of valence electrons in an element?

5. By using electron configurations
Electron configuration for chlorine: 1s22s22p63s23p5 What is the highest energy level reached? 3 How many electrons are there? 7

6. Because of trends, we can also use group numbers!
Looking at the electron configuration for elements in the same group, they will all have the same number of valence electrons (just the A groups though! Not the B groups.)

7. Guided Practice on Valence Electrons
How many valence electrons are there in the following elements? Chlorine Calcium Aluminum Carbon Neon

8. Electron Dot Structures
Also known as Lewis Structures
Diagrams that represent the number of valence electrons in the atom
Find number of valence electrons
Write element symbol
Fill valence electrons around symbol, one on each side first then double up

9. Guided Practice on Lewis Structures
Find the Lewis Dot Structures for the following elements: Chlorine Calcium Aluminum Carbon Neon

10. Octet Rule
Noble gases are the most stable elements on the Periodic Table due to the fact that they have 8 valence electrons (a complete outer shell)
Atoms will either lose or gain electrons through bonding in order to attain those complete 8 configurations
Metal elements tend to lose electrons while nonmetals tend to gain

11. Forming ions How do cations form? How do anions form?
Losing valence electrons
Who tends to form cations?
How do anions form?
Gaining valence electrons
Who tends to form anions?

13. Forming cations Metals Lose valence electrons Example: Calcium
Normal calcium calcium ion
20 protons 20 protons
20 electrons 18 electrons
no charge +2 charge

14. Forming anions Nonmetals Gain electrons to get to an octet
Example: Chlorine
normal chlorine chlorine ion
17 protons protons
17 electrons 18 electrons
no charge charge

15. Independent Practice

16. Formation of Ionic Compounds
Composed of a cation and an anion
Held together by ionic bonds
Represented by a chemical formula
A formula unit is the lowest whole-number ratio of ions in an ionic compound

17. Formation of Ionic Compounds
When writing the formulas, use the criss-cross method
Mg Cl-1
MgCl2

18. Showing Ionic Bonding with Lewis Structures

19. Showing Ionic Bonding with electron configurations

20. Guided Practice on Ionic Compound Formulas
For the following pairs of elements, write the formula for the ionic compound formed
Aluminum and Chlorine
Sodium and Sulfur
Nitrogen and fluorine

21. Independent Practice