1. Notes: Ionic Bonds and Lewis Dot Structures

2. How to Draw Lewis Structures

3. Lewis Structures Find your element on the periodic table.
Determine the number of valence electrons.
This is how many electrons you will draw.

4. Lewis Structures Find out which group (column) your element is in.
This will tell you the number of valence electrons your element has.
You will only draw the valence electrons.

5. Groups - Review Group 8 = 8 electrons Group 1 = 1 electron
Except for He, it has 2 electrons
Group 2 = 2 electrons
Each column is called a “group”
3, 4, 5, 6, 7
Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.
The electrons in the outer shell are called “valence electrons”

6. C Lewis Structures Write the element symbol.
Carbon is in the 4th group, so it has 4 valence electrons.
Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol. C

7. C Lewis Structures Check your work.
Using your periodic table, check that Carbon is in the 4th group.
You should have 4 total electrons, or dots, drawn in for Carbon. C

8. C Lewis Structures On your worksheet, try these elements on your own:P Ca Ar Cl Al C

9. Ionic Bonds

10. Bonding Atoms Why do atoms bond?
- each atom wants a full outermost energy level
- gain, lose, and share valence electrons to achieve the duet or octet rule aka: “being happy”
- gives each atom an electron configuration similar to that of a noble gas
ex. Group 18: He, Ne, Ar

11. Chemical Bonds Chemical Bonds
- attractive force that holds atoms or ions together
- 3 types
ionic, covalent, metallic
- determines the structure of compound
- structure affects properties
- melting/boiling pts, conductivity etc.

12. Ionic Bonds / Ionic Compounds
Definition
- bond formed by the attraction between oppositely charged ions
cation: positive: lost e-’s
anion: negative: gained e-’s
- oppositely charged ions attract each other and form an ionic bond
ex. Na+ + Cl- = NaCl
- electrons are transferred from one atom to another
- negative ions attract more positive ions, and soon a network is formed

13. Networks / Crystal Lattices
- repeating pattern of multiple ions
ex. NaCl
- every Na ion is next to 6 Cl ions
- strong attraction between ions creates a rigid framework, or lattice structure: aka: crystals
ex, cubes, hexagons, tetragons

14. Properties of Ionic Compounds
Structure affects properties
- strong attractions between ions: strong bonds
- high melting/boiling pt
- shatter when struck (think of it as one unit)
- conductivity
solid: ions are so close together, fixed positions, (can’t move)
NO conductivity
liquid: ions are freely moving due to a broken lattice structure
Good conductivity