I3- Ion Lewis Structure Concepts

The video tutorial explains how to draw the Lewis structure for the triiodide ion (I3-). It begins by counting the valence electrons using the periodic table, noting that iodine is in group 17 with seven valence electrons. With three iodine atoms and an extra electron due to the negative charge, there are 22 valence electrons in total. The tutorial then demonstrates placing electrons between iodine atoms to form bonds and completing the octets for the outer iodine atoms. It concludes by explaining the concept of an expanded octet for the central iodine atom and finalizing the structure with brackets and a negative charge.

What is the first step in drawing the Lewis structure for I3-?

• Determine the molecular geometry.

• Count the number of valence electrons.

• Calculate the formal charge.

• Identify the central atom.

How many valence electrons does each iodine atom contribute in I3-?

• 5

• 6

• 7

• 8

What is the total number of valence electrons in the I3- ion?

• 20

• 21

• 22

• 23

How are the iodine atoms arranged in the Lewis structure of I3-?

• In a linear arrangement.

• In a triangular arrangement.

• In a square arrangement.

• In a tetrahedral arrangement.

What is the purpose of placing electrons between iodine atoms in I3-?

• To form ionic bonds.

• To form covalent bonds.

• To form hydrogen bonds.

• To form metallic bonds.

What is an expanded octet, as seen in the I3- structure?

• An atom with less than 8 electrons.

• An atom with exactly 8 electrons.

• An atom with more than 8 electrons.

• An atom with no electrons.

Which iodine atom in I3- can have an expanded octet?

• The iodine on the right.

• The iodine on the left.

• All iodine atoms.

• The central iodine.

Why is it acceptable for the central iodine in I3- to have more than 8 electrons?

• Because it is a noble gas.

• Because it is a non-metal.

• Because iodine can have an expanded octet.

• Because it is a transition metal.

What is the significance of placing brackets around the I3- structure?

• To indicate a resonance structure.

• To indicate an ion with a negative charge.

• To indicate a neutral molecule.

• To indicate a positive charge.

What charge is indicated on the I3- ion in its Lewis structure?

• Positive two charge.

• Neutral charge.

• Negative one charge.

• Positive one charge.