I’m super excited to teach you the lewis structure of MgF2 in just 6 simple steps.
Infact, I’ve also given the step-by-step images for drawing the lewis dot structure of MgF2 molecule.
So, if you are ready to go with these 6 simple steps, then let’s dive right into it!
Lewis structure of MgF2 contains two single bonds between the Magnesium (Mg) atom and each Fluorine (F) atom. The Magnesium atom (Mg) is at the center and it is surrounded by 2 Fluorine atoms (F). The Magnesium does not have lone pairs while both the Fluorine 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 MgF2).
6 Steps to Draw the Lewis Structure of MgF2
Step #1: Calculate the total number of valence electrons
Here, the given molecule is MgF2. In order to draw the lewis structure of MgF2, first of all you have to find the total number of valence electrons present in the MgF2 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 MgF2
- For Magnesium:
Magnesium is a group 2 element on the periodic table.
Hence, the valence electron present in magnesium is 2 (see below image).
- For Fluorine:
Fluorine is a group 17 element on the periodic table.
Hence, the valence electrons present in fluorine is 7 (see below image).
Hence in a MgF2 molecule,
Valence electrons given by Magnesium (Mg) atom = 2
Valence electrons given by each Fluorine (F) atom = 7
So, total number of Valence electrons in MgF2 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 MgF2 molecule, if we compare the magnesium atom (Mg) and fluorine atom (F), then the magnesium is less electronegative than fluorine.
So, magnesium should be placed in the center and the remaining 2 fluorine atoms will surround it.
Step #3: Put two electrons between the atoms to represent a chemical bond
Now in the above sketch of MgF2 molecule, put the two electrons (i.e electron pair) between magnesium atom and fluorine atom to represent a chemical bond between them.
These pairs of electrons present between the Magnesium (Mg) and Fluorine (F) atoms form a chemical bond, which bonds the magnesium and fluorine atoms with each other in a MgF2 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 MgF2, the outer atoms are fluorine atoms.
So now, you have to complete the octet on these fluorine atoms (because fluorine requires 8 electrons to have a complete outer shell).
Now, you can see in the above image that all the fluorine atoms form an octet.
Also, all the 16 valence electrons of MgF2 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 MgF2.
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 magnesium) is stable or not.
The magnesium 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 magnesium), has 4 electrons. This indicates that the s-orbitals of magnesium 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 magnesium atom (Mg) as well as each fluorine atom (F).
For that, you need to remember the formula of formal charge;
Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2
- For Magnesium:
Valence electron = 2 (as it is in group 2)
Nonbonding electrons = 0
Bonding electrons = 4
- For Fluorine:
Valence electron = 7 (as it is in group 17)
Nonbonding electrons = 6
Bonding electrons = 2
|Formal charge||=||Valence electrons||–||Nonbonding electrons||–||(Bonding electrons)/2|
So you can see above that the formal charges on magnesium as well as fluorine are “zero”.
Hence, there will not be any change in the above structure and the above lewis structure of MgF2 is the final stable structure only.
Each electron pair (:) in the lewis dot structure of MgF2 represents the single bond ( | ). So the above lewis dot structure of MgF2 can also be represented as shown below.