Hi, this is Dr. B. Let’s do the Lewis structure for Beryllium Chloride.

On the periodic table, Beryllium is in Group 2. It has two valence electrons. Chlorine in Group 7 is 7, but we have two of those Chlorines. If we multiply that by 2 and add this, we get 16 total valence electrons.

Let’s draw it.

We’ll put the least electronegative, Beryllium, at the center. And on either side, we’ll put a Chlorine. And we have 16 valence electrons.

Put 2 between the atoms to form the bonds. So we have 2, 4, and then around the outside atoms, 6, 8, 10, 12, 14, 16. We’ve used up all the valence electrons, and let’s see if we have octets.

This is good on this Chlorine, and over here we’re fine. We have 8 on both.

But the Beryllium in the center only has 4. Well, I know that Beryllium is kind of an exception. It doesn’t necessarily need 8 valence electrons. So I’m not sure if this is the right structure.

The way to check is to use formal charges.

So we have an equation here to calculate the formal charge for each of the atoms.

So let’s start with this Chlorine right here. Chlorine’s in Group 7, so it has 7 valence electrons. Non-bonding, these ones right here, there are 6 of those. Non-bonding, there are 2 of those.

But we’re going to divide that by 2. 7-6-1 is 0. The formal charge on Chlorine is 0. And since both Chlorines are the same, that’s going to be 0, too.

OK, let’s check out the Beryllium right here.

So Beryllium is in Group 2, 2 valence electrons. Non-bonding, well, all of the valence electrons for Beryllium are involved in bonds, so that’s 0. Minus bonding, these right here, divided by 2. So 2-0-2 is 0. So the formal charge on Beryllium is also 0.

When the formal charges are all 0, then I’m comfortable that this is really going to be the best structure.

This is Dr. B., and thanks for watching.

# BeCl2 Lewis Structure: A Step-by-Step Guide

Discussion on Lewis structure of Beryllium Chloride; Beryllium exception reviewed.

## Key Insights

- The Lewis structure for Beryllium Chloride is being discussed.
- Beryllium is in Group 2 and has two valence electrons.
- Chlorine is in Group 7, and there are two Chlorines, giving a total of 16 valence electrons.
- The structure is drawn with Beryllium in the center and Chlorine on either side.
- The valence electrons are distributed, and all 16 have been used.
- The octet rule is checked, and the Chlorine atoms have eight valence electrons, but Beryllium only has four.
- Beryllium is an exception and doesn't necessarily require 8 valence electrons.
- Formal charges are introduced to verify the structure.
- The formal charge for Chlorine is calculated as 0.
- The formal charge for Beryllium is also calculated as 0.
- When all the formal charges are 0, it is determined that this is the best structure.
- The video was presented by Dr. B.