I’m super excited to teach you the lewis structure of KrF4 in just 5 simple steps.
Infact, I’ve also given the step-by-step images for drawing the lewis dot structure of KrF4 molecule.
So, if you are ready to go with these 5 simple steps, then let’s dive right into it!
Lewis structure of KrF4 contains four single bonds between the Krypton (Kr) atom and each Fluorine (F) atom. The Krypton atom (Kr) is at the center and it is surrounded by 4 Fluorine atoms (F). The Krypton atom has 2 lone pairs and all 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 KrF4).
5 Steps to Draw the Lewis Structure of KrF4
Step #1: Calculate the total number of valence electrons
Here, the given molecule is KrF4. In order to draw the lewis structure of KrF4, first of all you have to find the total number of valence electrons present in the KrF4 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 KrF4
- For Krypton:
Krypton is a group 18 element on the periodic table.
Hence, the valence electron present in krypton is also 8 (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 KrF4 molecule,
Valence electrons given by Krypton (Kr) atom = 8
Valence electrons given by each Fluorine (F) atom = 7
So, total number of Valence electrons in KrF4 molecule = 8 + 7(4) = 36
Step #2: Select the center atom
While selecting the atom, always put the least electronegative atom at the center.
Here in the KrF4 molecule, if we compare the krypton atom (Kr) and fluorine atom (F), then the krypton is less electronegative than fluorine.
So, krypton should be placed in the center and the remaining 4 fluorine atoms will surround it.
Step #3: Put two electrons between the atoms to represent a chemical bond
Now in the above sketch of KrF4 molecule, put the two electrons (i.e electron pair) between each krypton atom and fluorine atom to represent a chemical bond between them.
These pairs of electrons present between the Krypton (Kr) and Fluorine (F) atoms form a chemical bond, which bonds the krypton and fluorine atoms with each other in a KrF4 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 KrF4, 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, only 34 valence electrons of KrF4 molecule are used in the above structure.
But there are total 36 valence electrons in KrF4 molecule (as calculated in step #1).
So the number of electrons left to be kept on the central atom = 36 – 32 = 4.
So let’s keep these four electrons (i.e 2 electron pairs) on the central atom.
Now, let’s move to the next step.
Step #5: 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 krypton atom (Kr) 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 Krypton:
Valence electron = 8 (as it is in group 18)
Nonbonding electrons = 4
Bonding electrons = 8
- 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 krypton as well as fluorine are “zero”.
Hence, there will not be any change in the above structure and the above lewis structure of KrF4 is the final stable structure only.
Each electron pair (:) in the lewis dot structure of KrF4 represents the single bond ( | ). So the above lewis dot structure of KrF4 can also be represented as shown below.