# Problem: Although I3- is known, F3- is not.One of your classmates says F3- does not exist because it would violate the octet rule. Is this classmate possibly correct?

###### FREE Expert Solution

In this problem, we are asked to prove why I3- would exist, and F3- would not.

Recall that the octet rule states that an element is surrounded by eight electrons in the Lewis structure.

Exceptions to this rule occur when:

• there is an odd number of electrons, like in radicals

• there are less than 8 electrons or incomplete octet

• there are more than 8 electrons or expanded octet. This occurs to nonmetals from Period 3 to 7.

For this problem, we need to draw the Lewis structure for I3-, and F3-.

To do so, we need the following steps:

Step 1: Determine the central atom in this molecule.

Step 2: Calculate the total number of valence electrons present.

Step 3: Draw the Lewis structure for the molecule.

94% (198 ratings) ###### Problem Details

Although I3- is known, F3- is not.

One of your classmates says F3- does not exist because it would violate the octet rule. Is this classmate possibly correct?