I2 Lewis structure

I₂ (iodine) has two iodine atoms.

In the I₂ Lewis structure, there is a single bond between the two iodine atoms, and on each iodine atom, there are three lone pairs.

Alternative method: Lewis structure of I₂

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, iodine lies in group 17. Hence, iodine has seven valence electrons.

Since I₂ has two iodine atoms, so…

Valence electrons of two iodine atoms = 7 × 2 = 14

So the total valence electrons = 14

• Second, find the total electron pairs

We have a total of 14 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 14 ÷ 2 = 7

• Third, determine the central atom

Here, there are only two atoms and both atoms are iodine, so we can assume any one as the central atom.

Let’s assume that the central atom is right iodine.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 7 electron pairs. And one I — I bond is already marked. So we have to only mark the remaining six electron pairs as lone pairs on the sketch.

Also remember that iodine is a period 5 element, so it can keep more than 8 electrons in its last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atom is left iodine.

So for each iodine, there are three lone pairs.

Mark the lone pairs on the sketch as follows:

Formal charge

Use the following formula to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

For each iodine atom, formal charge = 7 – 6 – ½ (2) = 0

Here, both iodine atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of I₂ comprises two iodine atoms linked to each other by a single covalent bond. In this layout, each iodine atom satisfies the octet rule by retaining three lone pairs alongside the single shared pair of electrons. This arrangement represents the most stable state for the molecule because it results in a formal charge of zero for both atoms. Consequently, this specific electronic distribution serves as the definitive and most accurate Lewis representation of molecular iodine.

Next: Acetone Lewis structure

External video

• I2 Lewis Structure – How to Draw the Dot Structure for I2 – YouTube • Wayne Breslyn

External links

• https://www.chemistryscl.com/general/I2-lewis-structure/
• https://www.thegeoexchange.org/chemistry/bonding/Lewis-Structures/I2-lewis-structure.html
• https://lambdageeks.com/iodine-lewis-dot-structure/
• https://sciedutut.com/i2-lewis-structure/