What is the Ionic Charge of Iodine (I)? And Why?

The Ionic Charge of Iodine (I) is 1-.

But the question is how can you find the ionic charge on Iodine (I)?

Well there are 2 methods by which you can find the ionic charge of Iodine (I).

Lets dive right into these methods one by one.

If you are a visual learner like me, then here is a short one minute video for you.

Method 1: By looking at the ionic charge trends on periodic table

This is a very simple method to determine the ionic charge of the monatomic ions.

First of all, let’s look at the group-wise ionic charge trends on the periodic table.

You can see in the above periodic table that; 

• Elements of group 1 have 1+ ionic charge,

• Elements of group 2 have 2+ ionic charge,

(Exclude transition metals, because they have variable ionic charges)

• Elements of group 13 have 3+ ionic charge,

(Exclude group 14, because they can have 4+ or 4- ionic charges)

• Elements of group 15 have 3- ionic charge,

• Elements of group 16 have 2- ionic charge,

• Elements of group 17 have 1- ionic charge,

• Elements of group 18 have 0 ionic charge,

Now here our element is Iodine (I) which lies in group 17 of the periodic table.

Hence the ionic charge of Iodine (I) is 1-.

Note:
The blank area shown in the above periodic table are mostly the transition and post-transition elements.
They show variable ionic charge.
Hence we cannot find their ionic charge by simply looking at the periodic table.
In order to find the charge of these elements, we need to look at what it is bonded with.
For more information, read the example of finding the charge of Copper.

Okay so now let’s see another method to find the ionic charge of Iodine (I).

Method 2: By using electron configuration

The electron configuration of Iodine is: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁵ or [Kr] 4d¹⁰ 5s² 5p⁵. ^[1]

You can see that the outermost orbit of Iodine has 7 electrons.

During the chemical reaction, iodine gains 1 electron and achieves the nearest noble gas configuration to become stable.

And as the Iodine (I) gains 1 electron, it forms I^– ion. 

Hence the ionic charge of Iodine (I) is 1-.

I hope you have understood the reason behind the 1- charge of iodine. 

Check out some other related topics for your practice.

Related topics:
Charge on CO3 (Carbonate ion)
Charge of Beryllium (Be)
Charge of Sulfur (S)
Charge on PO4 (Phosphate ion)
Charge of Silver (Ag)