Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

4. Molecular Compounds

Lewis Dot Structures: Exceptions (Simplified)

GOB Chemistry

4. Molecular Compounds

Lewis Dot Structures: Exceptions (Simplified)

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Multiple Choice

Metalloids can sometimes adopt the bonding preferences of similar nonmetals. Based on your knowledge of expanded octets, draw the Lewis Dot Structure for the following ion, SiF₆^2–.

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Identify the central atom in the ion, which is silicon (Si). Silicon is a metalloid and can have an expanded octet.

Determine the total number of valence electrons available. Silicon has 4 valence electrons, and each fluorine (F) atom has 7 valence electrons. Since there are 6 fluorine atoms, this contributes 42 electrons. Additionally, the 2- charge adds 2 more electrons, totaling 48 valence electrons.

Place the silicon atom in the center and arrange the six fluorine atoms around it. Each fluorine atom will form a single bond with silicon, using 2 electrons per bond, which accounts for 12 electrons (6 bonds x 2 electrons).

Distribute the remaining electrons to satisfy the octet rule for each fluorine atom. Each fluorine atom needs 8 electrons to complete its octet, including the electrons in the bond with silicon. Therefore, each fluorine will have 6 non-bonding electrons (3 lone pairs).

Ensure the silicon atom has an expanded octet, which is possible for elements in the third period and beyond. Silicon will have 12 electrons around it, accommodating the 6 bonds with fluorine.