Valence Electrons and Lewis Structures

The video tutorial explains how to draw the Lewis structure for the carbonate ion (CO3 2-). It begins by counting the total valence electrons, placing carbon at the center, and arranging the oxygen atoms around it. Initial bonds are formed, and electrons are distributed to complete the octets. The tutorial then addresses the need to adjust for formal charges by forming a double bond, ensuring the structure is correct. Finally, it explains the importance of using brackets to denote the ion's charge.

How many total valence electrons are present in the carbonate ion (CO3 2-)?

• 26

• 22

• 20

• 24

Which atom is placed at the center of the carbonate ion's Lewis structure?

• Oxygen

• Carbon

• Nitrogen

• Hydrogen

How many valence electrons are initially used to form bonds between the carbon and oxygen atoms?

• 10

• 4

• 6

• 8

What adjustment is made to ensure the carbon atom satisfies the octet rule?

• Remove electrons from oxygen

• Form a double bond with one oxygen

• Form a triple bond with one oxygen

• Add more electrons to carbon

What is the formal charge on the carbon atom in the carbonate ion's Lewis structure?

• -1

• +2

• 0

• +1

What is the overall charge of the carbonate ion?

• 0

• -2

• +1

• -1

Why are brackets used in the Lewis structure of the carbonate ion?

• To separate different resonance structures

• To indicate the presence of a double bond

• To show the ion's charge

• To highlight the central atom