BeCl2 Lewis structure

BeCl₂ (beryllium chloride) has one beryllium atom and two chlorine atoms.

In the BeCl₂ Lewis structure, there are two single bonds around the beryllium atom, with two chlorine atoms attached to it, and on each chlorine atom, there are three lone pairs.

Alternative method: Lewis structure of BeCl₂

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, beryllium lies in group 2, and chlorine lies in group 17.

Hence, beryllium has two valence electrons and chlorine has seven valence electrons.

Since BeCl₂ has one beryllium atom and two chlorine atoms, so…

Valence electrons of one beryllium atom = 2 × 1 = 2
Valence electrons of two chlorine atoms = 7 × 2 = 14

And the total valence electrons = 2 + 14 = 16

Learn how to find: Beryllium valence electrons and Chlorine valence electrons

• Second, find the total electron pairs

We have a total of 16 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 = 16 ÷ 2 = 8

• Third, determine the central atom

We have to place the least electronegative atom at the center.

Since beryllium is less electronegative than chlorine, assume that the central atom is beryllium.

Therefore, place beryllium in the center and chlorines on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 8 electron pairs. And two Be — Cl bonds are already marked. So we have to only mark the remaining six electron pairs as lone pairs on the sketch.

Also remember that beryllium is a period 2 element, so it can not keep more than 8 electrons in its last shell. And chlorine is a period 3 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 atoms are chlorines.

So for each chlorine, there are three lone pairs, and for beryllium, there is zero lone pair because all six electron pairs are over.

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 beryllium atom, formal charge = 2 – 0 – ½ (4) = 0

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

Here, both beryllium and chlorine atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of BeCl₂ features a central beryllium atom linked to two chlorine atoms through single covalent bonds. In this arrangement, the beryllium atom acts as an electron-deficient center, accommodating only four electrons in its valence shell to form these two bonds. Within this layout, each chlorine atom successfully fulfills the octet rule by retaining three lone pairs alongside its single shared bond. This configuration represents the most stable state for the gaseous monomer because it results in a formal charge of zero for every atom involved. Thus, this specific electronic distribution serves as the definitive and most accurate Lewis representation of beryllium chloride.

Next: N₂F₂ Lewis structure

External video

• How to Draw the Lewis Dot Structure for BeCl2: Beryllium chloride – YouTube • Wayne Breslyn

External links

• https://geometryofmolecules.com/becl2-lewis-structure-molecular-geometry-hybridization-bond-angle-shape/
• https://techiescientist.com/becl2-lewis-structure/
• https://www.thegeoexchange.org/chemistry/bonding/Lewis-Structures/BeCl2-lewis-structure.html
• https://topblogtenz.com/becl2-lewis-structure-molecular-geometry-polar-or-nonpolar-bond-angle/
• https://lambdageeks.com/becl2-lewis-structure/