1. Periodic Table Study Guide
How to Draw Lewis Structures

2. Lewis Structures
Determine the number of valence electrons. It is equal to the group #, or valence
This is how many electrons you will draw.

3. 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.

4. 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”

5. 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

6. 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

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

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

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

10. Lewis Structures On your worksheet, try these elements on your own: HP Ca Ar Cl Al

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

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

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

14. Chemical Bonds

15. Learning Objectives
Understand what a covalent bond is and what an ionic bond is and how they are different

16. Ionic Bond
Between atoms of metals and nonmetals with very different electronegativity
Bond formed by transfer of electrons
Produce charged ions all states. Conductors and have high melting point.
Examples; NaCl, CaCl2, K2O

18. Ionic Bonds: One Big Greedy Thief Dog!

19. Continuous Ionic Crystals

20. COVALENT BOND bond formed by the sharing of electrons of close electronegativity <0.7

21. Figure 12.3: Electronegativity values for selected elements.
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22. Covalent Bond
Between nonmetallic elements of similar electronegativity.
Formed by sharing electron pairs
Non-metals to non-metals
Examples; O2, CO2, C2H6, H2O, SiC

23. Covalent Bonds

24. 2. Covalent bonds- Two atoms share one or more pairs of outer-shell electrons.
Oxygen Atom
Oxygen Atom
Oxygen Molecule (O2)

25. Covalent Bonds: Willing to share.