Valence Electrons and Lewis Structures

Dr. B explains the process of drawing the Lewis structure for SO3. Starting with the valence electrons, he places sulfur at the center and distributes electrons to form initial bonds. He then adjusts the structure to achieve an octet for each atom, calculates formal charges, and modifies the structure to achieve zero formal charges, resulting in the best Lewis structure for SO3.

How many valence electrons does sulfur have in the SO3 molecule?

• 10

• 6

• 4

• 8

What is the total number of valence electrons in the SO3 molecule?

• 18

• 26

• 20

• 24

Where is sulfur placed in the initial Lewis structure of SO3?

• At the center

• On the outside

• Next to one oxygen

• Between two oxygens

What is the initial problem with the sulfur atom in the SO3 Lewis structure?

• It is not central

• It has too few electrons

• It has too many electrons

• It is not bonded

Why can sulfur hold more than 8 electrons in its valence shell?

• It is in the first period

• It is a metal

• It is in the second period

• It is in the third period

What adjustment is made to improve the SO3 Lewis structure?

• Add more electrons

• Remove electrons

• Form double bonds

• Change the central atom

How many double bonds are present in the final SO3 Lewis structure?

• Four

• Three

• Two

• One

What is the formal charge on each oxygen atom in the final SO3 structure?

• +2

• -1

• 0

• +1

What is the formal charge on the sulfur atom in the final SO3 structure?

• -1

• +2

• +1

• 0

What makes the final Lewis structure of SO3 the best one?

• Sulfur has a positive charge

• All atoms have a formal charge of zero

• Oxygens have extra electrons

• Sulfur is not central