Lewis Structure of BeH2 (With 6 Simple Steps to Draw!)

I’m super excited to teach you the lewis structure of BeH2 in just 6 simple steps.

Infact, I’ve also given the step-by-step images for drawing the lewis dot structure of BeH2 molecule.

So, if you are ready to go with these 6 simple steps, then let’s dive right into it!

Lewis structure of BeH2 contains two single bonds between the Beryllium (Be) atom and each Hydrogen (H) atom. The Beryllium atom (Be) is at the center and it is surrounded by 2 Hydrogen atoms (H).

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 BeH2).

6 Steps to Draw the Lewis Structure of BeH2

Step #1: Calculate the total number of valence electrons

Here, the given molecule is BeH2 (beryllium hydride). In order to draw the lewis structure of BeH2, first of all you have to find the total number of valence electrons present in the BeH2 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 BeH2

• For Beryllium: 

Beryllium is a group 2 element on the periodic table. ^[1]

Hence, the valence electron present in beryllium is 2 (see below image).

• For Hydrogen: 

Hydrogen is a group 1 element on the periodic table. ^[2]

Hence, the valence electron present in hydrogen is 1 (see below image).

Hence in a BeH2 molecule, 

Valence electrons given by Beryllium (Be) atom = 2
Valence electrons given by each Hydrogen (H) atom = 1
So, total number of Valence electrons in BeH2 molecule = 2 + 1(2) = 4

Step #2: Select the center atom (H is always outside)

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). ^[3]

Here in the BeH2 molecule, if we compare the beryllium atom (Be) and hydrogen atom (H), then hydrogen is less electronegative than beryllium. But as per the rule, we have to keep hydrogen outside.

So, beryllium should be placed in the center and the remaining 2 hydrogen atoms will surround it.

Step #3: Put two electrons between the atoms to represent a chemical bond

Now in the above sketch of BeH2 molecule, put the two electrons (i.e electron pair) between beryllium atom and hydrogen atom to represent a chemical bond between them.

These pairs of electrons present between the Beryllium (Be) and Hydrogen (H) atoms form a chemical bond, which bonds the beryllium and hydrogen atoms with each other in a BeH2 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 BeH2, the outer atoms are hydrogen atoms.

So now, you have to check whether these hydrogen atoms are forming a duplet or not! (because hydrogen requires only 2 electrons to have a complete outer shell).

You can see in the above image that both the hydrogen atoms form a duplet.

Also, all the 4 valence electrons of BeH2 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 BeH2.

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 hydrogen atom (H).

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 Hydrogen:
  Valence electron = 1 (as it is in group 1)
  Nonbonding electrons = 0
  Bonding electrons = 2

Formal charge	=	Valence electrons	–	Nonbonding electrons	–	(Bonding electrons)/2
Be	=	2	–	0	–	4/2	=	0
H	=	1	–	0	–	2/2	=	0

So you can see above that the formal charges on beryllium as well as hydrogen are “zero”.

Hence, there will not be any change in the above structure and the above lewis structure of BeH2 is the final stable structure only.

Each electron pair (:) in the lewis dot structure of BeH2 represents the single bond ( | ). So the above lewis dot structure of BeH2 can also be represented as shown below.

Related lewis structures for your practice:
Lewis structure of HNO
Lewis structure of NI3
Lewis structure of CH2F2
Lewis structure of CH3-
Lewis structure of I2

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