Drawing Lewis Structures of Polyatomic Ions

This lesson, part of Unit 6, focuses on drawing Lewis structures for polyatomic ions, which are charged groups of covalently bonded atoms. The video explains the concept of polyatomic ions, their commonality in chemistry, and the process of drawing their Lewis structures. Two examples, NH4+ and CO32-, are provided to illustrate the method. The lesson concludes with practice exercises for students to reinforce their understanding.

What is a polyatomic ion?

• A group of covalently bonded atoms with a charge

• A single atom with a charge

• A molecule with no charge

• A single atom with no charge

What does the term 'polyatomic' mean?

• Two atoms

• No atoms

• One atom

• Many atoms

How do you adjust the number of electrons when drawing a Lewis structure for a negatively charged polyatomic ion?

• Do nothing

• Add electrons

• Add protons

• Remove electrons

What is the first step in drawing the Lewis structure for NH4+?

• Subtract protons

• Determine the total number of valence electrons

• Place hydrogen in the center

• Connect everything with a bond

How many valence electrons does nitrogen bring in NH4+?

• 6

• 5

• 4

• 3

Why can't hydrogen be placed in the center of the NH4+ Lewis structure?

• It has too many valence electrons

• It can only form one bond

• It is too electronegative

• It is too large

What is the total number of valence electrons available for bonding in CO32-?

• 18

• 22

• 24

• 20

Which atom is placed in the center when drawing the Lewis structure for CO32-?

• Oxygen

• Carbon

• Hydrogen

• Nitrogen

How do you ensure that the central atom in CO32- has a complete octet?

• Add protons

• Add more electrons

• Remove electrons

• Share electrons from outer atoms

What should be done after completing the Lewis structure for a polyatomic ion?

• Add protons

• Add more bonds

• Remove extra electrons

• Put brackets around the structure and add the charge