1. Lewis Diagrams of Atoms:
a. How many valence electrons does:
i. Ga have?
ii. I have?
iii. any alkaline earth metal have?
iv. Cesium have?
v. Any noble gas, row 2 and higher, have?
b. Why did we draw the Lewis diagrams for atoms of N with two electrons together and three electrons separate around the symbol?
c. Draw the Lewis Diagrams for three row 5 main-groups elements (groups 1-2, 13-18)
2. Lewis Diagrams of Ionic Compounds
Use Lewis diagrams to show the reaction of calcium with S and calcium with Br. Show how the final formulas are determined for each. Which will have a higher melting point?
3. Why do atoms form covalent bonds?
4. Are the bonds shown polar or pure covalent? If polar, assign partial charges based on electronegativity to each atom using the Ī“+/Ī“- symbols above the atom. Then choose which of the following bonds is most polar.
a. F-F
b. F-I
c. I-Cl
d. Cl-O
e. Cl-N
f. Br-N
5. Draw the Lewis structure of OFā. Indicate on the structure which electrons are bond pairs and which are lone pairs.
6. Lewis Diagrams of Molecular Compounds: Draw the Lewis diagram for each.
a. CFā
b. SiClā
c. PBrā
d. HāS
e. POāĀ³ā»
7. Determine the formal charge for each atom in the structures drawn in number 6.
8. Draw the resonance forms of COāĀ²ā». What kind of bond is between each C and O?
9. A student has to draw the Lewis structure for hypochlorous acid. They are unsure if the atoms should be linked as HOCl or OClH. Draw each structure, assign formal charges to each atom and use them to explain why Cl or O should be the center atom.