Valence Electrons and Lewis Structures

The video tutorial explains how to draw the Lewis structure for the SeO3 2- ion. It begins by counting the valence electrons, placing selenium in the center, and arranging the oxygen atoms around it. The tutorial then shows how to form chemical bonds and complete the octets. It addresses the issue of formal charges and demonstrates how to adjust them for stability. Finally, the video discusses resonance structures and how they contribute to the overall structure of the ion.

How many total valence electrons are present in SeO3 2-?

• 30

• 26

• 24

• 28

Which element is placed at the center of the Lewis structure for SeO3 2-?

• Sulfur

• Nitrogen

• Selenium

• Oxygen

What is the purpose of placing electrons between atoms in a Lewis structure?

• To complete the octet

• To form chemical bonds

• To reduce formal charge

• To increase electronegativity

How many valence electrons are used after completing the octets on the outer atoms in SeO3 2-?

• 24

• 22

• 26

• 20

What is the goal when adjusting formal charges in a Lewis structure?

• To increase the number of lone pairs

• To make formal charges as close to zero as possible

• To maximize the number of bonds

• To decrease the total number of electrons

What should be done to indicate that SeO3 2- is an ion in its Lewis structure?

• Add more electrons

• Draw a circle around it

• Use a different color

• Put brackets around the structure

What is the formal charge on the central selenium atom after adjusting the electrons?

• +1

• -2

• -1

• 0

What are resonance structures?

• Structures with different central atoms

• Structures with different arrangements of electrons

• Structures with different numbers of electrons

• Structures with different atoms

How many resonance structures are possible for SeO3 2-?

• 2

• 4

• 1

• 3

What is the average of resonance structures used to represent?

• The actual structure of the molecule

• The structure with the most bonds

• The least stable structure

• The most stable structure