Valence Electrons and Lewis Structures

The video tutorial explains how to write the Lewis structure for ASO2-. It begins by counting the valence electrons, placing the least electronegative element at the center, and forming initial bonds. The tutorial then shows how to complete the octets and form double bonds to satisfy the octet rule. It concludes with an explanation of resonance structures, highlighting that the bonds are an average of the possible structures.

What is the total number of valence electrons in the ASO2- ion?

• 22

• 20

• 18

• 16

Which element is placed at the center of the ASO2- Lewis structure?

• Nitrogen

• Oxygen

• Sulfur

• Arsenic

How many oxygen atoms are present in the ASO2- ion?

• One

• Four

• Two

• Three

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

• To change the element

• To decrease the number of electrons

• To increase the number of electrons

• To form a chemical bond

How many valence electrons are used to complete the octets on the oxygen atoms?

• 16

• 14

• 12

• 10

What adjustment is made to ensure the central arsenic atom has an octet?

• Change the central atom

• Add more electrons

• Form a double bond

• Remove electrons

What is the result of moving two electrons to form a double bond in the ASO2- structure?

• The structure becomes unstable

• Arsenic gains an octet

• The ion becomes neutral

• Oxygen loses its octet

What does the presence of a double bond in the ASO2- structure indicate?

• No resonance

• Resonance is possible

• The structure is incorrect

• The ion is unstable

What is the effect of resonance on the bond lengths in the ASO2- structure?

• Increased bond lengths

• No effect on bond lengths

• Same bond lengths

• Different bond lengths

What is the final step in completing the Lewis structure for ASO2-?

• Adding more electrons

• Changing the central atom

• Drawing resonance structures

• Placing brackets and a negative sign