Ready to learn how to draw the lewis structure of BeCl2?
Here, I have explained 6 simple steps to draw the lewis dot structure of BeCl2 (along with images).
So, if you are ready to go with these 6 simple steps, then let’s dive right into it!
Lewis structure of BeCl2 contains two single bonds between the Beryllium (Be) atom and each Chlorine (Cl) atom. The Beryllium atom (Be) is at the center and it is surrounded by 2 Chlorine atoms (Cl). The Beryllium does not have lone pairs while both the Chlorine atoms have 3 lone pairs.
Let’s draw and understand this lewis dot structure step by step.
(Note: Take a pen and paper with you and try to draw this lewis structure along with me. I am sure you will definitely learn how to draw lewis structure of BeCl2).
6 Steps to Draw the Lewis Structure of BeCl2
Step #1: Calculate the total number of valence electrons
Here, the given molecule is BeCl2 (beryllium chloride). In order to draw the lewis structure of BeCl2, first of all you have to find the total number of valence electrons present in the BeCl2 molecule.
(Valence electrons are the number of electrons present in the outermost shell of an atom).
So, let’s calculate this first.
Calculation of valence electrons in BeCl2
- For Beryllium:
Beryllium is a group 2 element on the periodic table.
Hence, the valence electron present in beryllium is 2 (see below image).
- For Chlorine:
Chlorine is a group 17 element on the periodic table.
Hence, the valence electron present in chlorine is 7 (see below image).
Hence in a BeCl2 molecule,
Valence electrons given by Beryllium (Be) atom = 2
Valence electrons given by each Chlorine (Cl) atom = 7
So, total number of Valence electrons in BeCl2 molecule = 2 + 7(2) = 16
Step #2: Select the center atom
While selecting the atom, always put the least electronegative atom at the center.
(Remember: Fluorine is the most electronegative element on the periodic table and the electronegativity decreases as we move right to left in the periodic table as well as top to bottom in the periodic table).
Here in the BeCl2 molecule, if we compare the beryllium atom (Be) and chlorine atom (Cl), then the beryllium is less electronegative than chlorine.
So, beryllium should be placed in the center and the remaining 2 chlorine atoms will surround it.
Step #3: Put two electrons between the atoms to represent a chemical bond
Now in the above sketch of BeCl2 molecule, put the two electrons (i.e electron pair) between beryllium atom and chlorine atom to represent a chemical bond between them.
These pairs of electrons present between the Beryllium (Be) and Chlorine (Cl) atoms form a chemical bond, which bonds the beryllium and chlorine atoms with each other in a BeCl2 molecule.
Step #4: Complete the octet (or duplet) on outside atoms. If the valence electrons are left, then put the valence electrons pair on the central atom
Don’t worry, I’ll explain!
In the Lewis structure of BeCl2, the outer atoms are chlorine atoms.
So now, you have to complete the octet on these chlorine atoms (because chlorine requires 8 electrons to have a complete outer shell).
Now, you can see in the above image that all the chlorine atoms form an octet.
Also, all the 16 valence electrons of BeCl2 molecule (as calculated in step #1) are used in the above structure. So there are no remaining electron pairs.
Hence there is no change in the above sketch of BeCl2.
Let’s move to the next step.
Step #5: Check whether the central atom is stable or not
In this step, we have to check whether the central atom (i.e beryllium) is stable or not.
The beryllium atom does not require 8 electrons in its outer orbit to become stable.
As you can see from the above image, the central atom (i.e beryllium), has 4 electrons. This indicates that the s-orbitals of beryllium are completely filled. So it is stable.
Step #6: Final step – Check the stability of lewis structure by calculating the formal charge on each atom
Now, you have come to the final step and here you have to check the formal charge on beryllium atom (Be) as well as each chlorine atom (Cl).
For that, you need to remember the formula of formal charge;
Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2
- For Beryllium:
Valence electron = 2 (as it is in group 2)
Nonbonding electrons = 0
Bonding electrons = 4
- For Chlorine:
Valence electron = 7 (as it is in group 17)
Nonbonding electrons = 6
Bonding electrons = 2
So you can see above that the formal charges on beryllium as well as chlorine are “zero”.
Hence, there will not be any change in the above structure and the above lewis structure of BeCl2 is the final stable structure only.
Each electron pair (:) in the lewis dot structure of BeCl2 represents the single bond ( | ). So the above lewis dot structure of BeCl2 can also be represented as shown below.