Formal Charge and Lewis Structures

The video tutorial explains how to draw the Lewis structure for the PS3- ion. It begins by discussing the concept of expanded octets for elements in period three, like phosphorus, and the importance of minimizing formal charges. The tutorial then guides viewers through the process of arranging valence electrons to form chemical bonds, adjusting the structure to achieve the most stable configuration with minimal formal charges. The final structure is presented with the correct ion representation, including brackets and a negative sign.

What is a unique feature of elements in period three and below on the periodic table?

• They do not form ions.

• They are always metals.

• They can have an expanded octet.

• They can only have eight valence electrons.

Why is it important to consider formal charges when drawing Lewis structures?

• To ensure the structure is colorful.

• To make sure the structure is symmetrical.

• To keep formal charges as close to zero as possible.

• To maximize the number of bonds.

In the initial setup of the PS3 minus Lewis structure, which element is placed at the center?

• Oxygen

• Nitrogen

• Phosphorus

• Sulfur

What is the total number of valence electrons used in the PS3 minus Lewis structure?

• 32

• 18

• 28

• 24

What adjustment is made to ensure phosphorus achieves an octet in the PS3 minus structure?

• Adding more electrons to phosphorus.

• Forming a double bond with sulfur.

• Removing electrons from sulfur.

• Adding a new atom to the structure.

What is the formal charge on phosphorus before any double bonds are formed?

• +1

• 0

• -1

• +2

How is the formal charge issue resolved in the PS3 minus structure?

• By changing the central atom.

• By removing electrons from phosphorus.

• By forming another double bond.

• By adding more electrons to sulfur.

Which sulfur atom retains a negative formal charge in the final structure?

• The sulfur with a single bond.

• The sulfur with a double bond.

• The sulfur at the center.

• The sulfur at the bottom.

What should be added to the Lewis structure to indicate it is an ion?

• Brackets and a minus sign.

• A circle around the structure.

• A positive sign.

• A star symbol.

What is the overall charge of the PS3 minus ion?

• 0

• -2

• -1

• +1