1. Notes: Lewis Dot Structures Part 2
Chemistry
Boon
Date: 09/10 & 09/
Notes: Lewis Dot Structures Part 2

2. Catalyst: Mystery Molecules
Write the name of the molecule described:
This molecule consists of three atoms. Two of the atoms are of the same element. The molecule has two covalent bonds. This molecule makes up about 60% of a person’s body weight. It also covers about 70% of the earth.
This molecule consists of 24 atoms. This molecule is made of atoms of 3 elements. It is the product of photosynthesis and the reactant of cellular respiration.

3. Catalyst Answer 1
Water! H2O

4. Catalyst Answer 2
Glucose C6H12O6

5. Biology rewind: macromolecules
All organisms (living things) are made of macromolecules.
Macromolecules are covalent compounds.
The atoms in proteins, carbohydrates, nucleic acids, and lipids are all connected by covalent bonds.

6. Objectives
I can draw Lewis structures of molecules with single, double, or triple bonds.
I know that most biological compounds are formed by covalent bonds.
I can state that one mole is 6.02 x particles.

7. Agenda Catalyst HW Review Lewis Dot Structures of Molecules Part 2
Carbon Monoxide Reading Activity
Covalent Bonds Exit Slip
Demonstration: Intro to the Mole
Electron Configuration Practice

8. HW: Drawing Molecules WS
An electron in the outermost energy level of an atom that can participate in bonding is called a valence electron.
A structure in which atomic symbols represent nuclei and inner-shell electrons and in which dots are used to represent valence electrons is called a Lewis structure.
A possible Lewis structure of a molecule for which more than one Lewis structure can be written is called a resonance structure.

9. HW: Drawing Molecules WS
A covalent bond in which two atoms share two pairs of electrons is called a double bond.
A covalent bond in which two atoms share three pairs of electrons is called a triple bond.
A bond in which two atoms share one pair of electrons is called a single bond.
A nonbonding pair of electrons in the valence shell of an atom is called an unshared pair.

10. HW: Drawing Molecules WS
8. Methanol CH3OH 9. Propane C3H8

11. HW: Drawing Molecules WS
10. Water H2O
11. carbon monoxide CO

12. HW: Drawing Molecules WS
12. Nitryl fluoride NO2F SO32-

13. HW Vocabulary Crossword
Down
Proton
Halogen
4. Cation
Anion
Isotope
Electron configuration
Noble gas
Electronegativity
Valence electron
Mass number
Across
Atomic mass
Atomic number
Ion
Period
13. Orbital
16. Nucleus
17. Crystal lattice
Octet rule
Alkali metal
Group

14. Notes: Lewis Dot Structures part 2
Chemistry
Date: 09/10 & 09/
Notes: Lewis Dot Structures part 2

15. Lewis Dot Structures: Part 2
In a covalent bond, atoms share electrons.

16. Lewis Dot Structures: Part 2
A covalent bond in which two atoms share two pairs of electrons is called a double bond.

17. Lewis Dot Structures: Part 2
A covalent bond in which two atoms share three pairs of electrons is called a triple bond.

18. Rules for covalent bonding
Each bond is made up of 2 electrons
Each atom wants to reach the same configuration as the noble gases
Duet rule: Hydrogen wants 2 valence electrons
Octet rule: All other atoms want 8 valence electrons
Atoms will share electrons with other atoms so that both get a full valence shell

19. Drawing Lewis Dots for Compounds
CH4
Steps:
1. Draw Lewis Dot structures for the individual atoms
Double check your numbers of valence e-
2. Put central atom in the center
3. Put other atoms around
4. Draw 2 dots between each pair
5. Fill in other dots up to 8 (except for H) – if the atoms do not have enough valence electrons to reach 8, a double or triple bond is necessary.
6. Replace all bonded pairs with lines
Central atom H H C H H

20. Double and Triple Bonds
What happens when the total electrons do not match up with the Lewis structure?
Example: O2
Draw the Lewis dot structure:
Total valence electrons: O O O2
= 2 x 6 = 12
Single bonded structure uses too many electrons!

21. Double Bonds
If the structure has too many dots, remove lone pairs from two atoms and replace with a double bond
In a double bond, the atoms share 4 electrons
Replace the bonded pairs with 2 lines
Lone pairs O O

22. Double Bonds C O Some atoms can have more than one double bond
Example: CO2
Total valence electrons: C
= 4 O2
= 2 x 6 = 12 C O 16

23. Practice Carbon dioxide: CO2 Carbon monoxide: CO Sulfur dioxide: SO2
Nitrogen gas: N2
Dibromoethene: C2H2Br2
Ethylene: C2H4

24. Agenda Catalyst HW Review Lewis Dot Structures of Molecules Part 2
Carbon Monoxide Reading Activity
Covalent Bonds Exit Slip
Demonstration: Intro to the Mole
Electron Configuration Practice

25. Carbon Monoxide Reading
Carbon monoxide is a very dangerous gas. This article provides vital information about this deadly gas.
Instructions: After each paragraph, ask yourself, “what did I just read?” and “why is this important?” If you cannot answer these questions, go back and reread the paragraph.
After reading, answer the questions at the bottom of the page.

26. Agenda Catalyst HW Review Lewis Dot Structures of Molecules Part 2
Carbon Monoxide Reading Activity
Covalent Bonds Exit Slip
Demonstration: Intro to the Mole
Electron Configuration Practice

27. Agenda Catalyst HW Review Lewis Dot Structures of Molecules Part 2
Carbon Monoxide Reading Activity
Covalent Bonds Exit Slip
Demonstration: Intro to the Mole
Electron Configuration Practice

28. Mole Demonstration…
Substance Name
Observations
Water H2O
Sodium Chloride NaCl
Sucrose C12H24O12
Oleic Acid C18H34O2
Potassium Chloride KCl
The mole is a number we use to make counting atoms, ions, and molecules much easier.
One mole is the number of carbon atoms in 12 grams of carbon-12.
One mole is x 1023 particles.

29. Homework Read textbook pp. 224-229
Due Wednesday 09.12:
Read textbook pp
Do problems: pp. 233 #1, 2, 4, 5, 6(a), 8(a)
Due Thursday or Friday or 09.14:
Valence electron and ions review WS