Ready to learn how to draw the lewis structure of GaI3?
Here, I have explained 5 simple steps to draw the lewis dot structure of GaI3 (along with images).
So, if you are ready to go with these 5 simple steps, then let’s dive right into it!
Lewis structure of GaI3 contains three single bonds between the Gallium (Ga) atom and each Iodine (I) atom. The Gallium atom (Ga) is at the center and it is surrounded by 3 Iodine atoms (I). The Gallium atom does not have a lone pair while all three iodine atoms have three lone pairs each.
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 GaI3).
5 Steps to Draw the Lewis Structure of GaI3
Step #1: Calculate the total number of valence electrons
Here, the given molecule is GaI3. In order to draw the lewis structure of GaI3, first of all you have to find the total number of valence electrons present in the GaI3 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 GaI3
- For Gallium:
Gallium is a group 13 element on the periodic table.
Hence, the valence electrons present in gallium is 3 (see below image).
- For Iodine:
Iodine is a group 17 element on the periodic table.
Hence, the valence electrons present in iodine is 7 (see below image).
Hence in a GaI3 molecule,
Valence electrons given by Gallium (Ga) atom = 3
Valence electrons given by each Iodine (I) atom = 7
So, total number of Valence electrons in GaI3 molecule = 3 + 7(3) = 24
Step #2: Select the center atom
While selecting the center 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 GaI3 molecule, if we compare the gallium atom (Ga) and iodine atom (I), then gallium is less electronegative than iodine.
So, gallium should be placed in the center and the remaining 3 iodine atoms will surround it.
Step #3: Put two electrons between the atoms to represent a chemical bond
Now in the above sketch of a GaI3 molecule, put the two electrons (i.e electron pair) between each gallium atom and iodine atom to represent a chemical bond between them.
These pairs of electrons present between the Gallium (Ga) and Iodine (I) atoms form a chemical bond, which bonds the gallium and iodine atoms with each other in a GaI3 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 GaI3, the outer atoms are iodine atoms.
So now, you have to complete the octet on these iodine atoms (because iodine requires 8 electrons to have a complete outer shell).
Now, you can see in the above image that all the iodine atoms form an octet.
Also, all the 24 valence electrons of GaI3 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 GaI3.
Let’s move to the next step.
Step #5: 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 gallium atom (Ga) as well as each iodine atom (I).
For that, you need to remember the formula of formal charge;
Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2
- For Gallium:
Valence electrons = 3 (as it is in group 13)
Nonbonding electrons = 0
Bonding electrons = 6
- For Iodine:
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 gallium as well as iodine are “zero”.
Hence, there will not be any change in the above structure and the above lewis structure of GaI3 is the final stable structure only.
Each electron pair (:) in the lewis dot structure of GaI3 represents the single bond ( | ). So the above lewis dot structure of GaI3 can also be represented as shown below.