1. Catalyst (5 minutes) Draw electron dot structures for the following elements (find the number of valence electrons!) ON A SEPARATE SHEET OF PAPER (KEEP IT FOR THE WEEK): 1. Chlorine 2. Carbon 3. Oxygen 4. Nitrogen Cl CN O

3. What we’ve learned so far…. Atoms lose/gain electrons to form cations and anions (8 valence electrons like a noble gas!) Charged anions and cations form IONIC BONDS to make IONIC COMPOUNDS FK + -

4. What we’re learning today… Atoms can also SHARE electrons to form COVALENT BONDS! Why is this important?  Covalent bonds are important in many organic molecules (living creatures)  Examples:  Cell membranes are made of lipids (We’d be puddles of liquid without them!)  Proteins (We’d starve without them!)

5. Covalent Bond The chemical bond formed when two atoms SHARE electrons  Why do atoms form bonds? To gain the same number of valence electrons as a noble gas! Cl Full octet (8)! Bonding Pair

6. Types of Covalent Bonds Single Bond: ONE pair of shared electrons Double Bond (Pi Bond): TWO pairs of shared electrons Triple Bond: THREE pairs of shared electrons Cl OO NN

7. How many bonds can an atom form? # bonds formed = # of UNPAIRED electrons # electrons atoms keep = # electrons in PAIRS NN 3 unpaired electrons = 3 bonds! O 2 pairs = four electrons the atom keeps!

8. Example 1 How many bonds can Sulfur form? How many electrons will Sulfur keep to itself? S Two unpaired electrons! Four electrons will be kept by sulfur! S Two pairs of electrons! Two bonds can be formed!

9. Example 2 How many bonds can Carbon form? How many electrons will Carbon keep to itself? C Four unpaired electrons! Zero electrons will be kept by carbon! C No pairs of electrons! Four bonds can be formed!

10. Example 3 How many bonds can Neon form? How many electrons will Neon keep to itself? Ne Zero unpaired electrons! Eight electrons will be kept by neon! Ne Four pairs of electrons! Zero bonds can be formed!

11. Announcements Homework – Due Fri Feb 4 Read Sec 8.1, pp 240-247 Define vocab on p 240 (7 words) Choose any 3 of the words and draw an illustration to show what they mean

12. Worksheet COMPLETE the worksheet