NF3 (Nitrogen trifluoride) Lewis Structure | Steps of Drawing
In the lewis structure of Nitrogen trifluoride (NF3), there are three N-F bonds and one lone pair on nitrogen atom. Each fluorine atom has three lone pairs. Lewis structure of NF3 can be drawn by starting from valence electrons of nitrogen and fluorine atoms in several steps. Each step of drawing the lewis structure of NF3 is explained in detail in this tutorial. After drawing the lewis structure of NF3, you can decide shape of the NF3 molecule.
NF3 lewis structure
In the lewis structure of NF3, there are three N-F bonds and one lone pair on nitrogen atom which is the center atom. Each fluorine atom has three lone pairs.
Steps of drawing lewis structure of NF3
You have to follow few steps to draw the lewis structure of NF3. Because nitrogen trifluoride is a simple molecule, these steps are not complex and do not require all steps which are used to draw lewis structures of complex molecules and ions. Those steps are explained in detail in next sections.
- Find total number of electrons of the valance shells of fluorine atoms and nitrogen atom
- Total electrons pairs as lone pairs and bonds
- Center atom selection
- Mark lone pairs on atoms
- Mark charges on atoms if there are charges on atoms.
- Check the stability and minimize charges on atoms by converting lone pairs to bonds to obtain best lewis structure.
Total number of electrons of the valance shells of NF3
There are two elements in NF3; fluorine and nitrogen. Fluorine is a group VIIA element and has seven electrons in its last shell (valence shell). Nitrogen is a group VA element in the periodic table and contains five electrons in its last shell. Now, we know how many electrons includes in valence shells of fluorine and nitrogen atoms.
To find out total valence electrons given by a particular element, you should multiply number of electrons of the valance shell by the number of atoms of that element.
- valence electrons given by fluorine atoms = 7 * 3 = 21
- valence electrons given by nitrogen atom = 5*1 = 5
- Total valence electrons = 21 + 5 = 26
Total valence electrons pairs
Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells
Total electron pairs are determined by dividing the number total valence electrons by two. For, NF3S, Total pairs of electrons are thirteen.
Center atom of NF3 molecule
To be the center atom, ability of having greater valance and being most electropositive element in the molecule are important.
- Maximum valence: Nitrogen's maximum valence is 5. Fluorine's maximum valence is 1. From that fact, nitrogen has the high priority to be the center atom.
- Most electropositive element: Nitrogen's and fluorine's electronegativity values are 2.1 and 4.0 respectively. in this case, phosphorus is more electropositive than fluorine. In this occasion too, nitrogen has the highest chance to be the center atom.
- From above 1 and 2 facts, it is clear that nitrogen atom should be the center atom.
Lone pairs on atoms
Now we have found the center atom and sketch of NF3 molecule. Now, we can start to mark lone pairs on atoms. Remember that, there are total of thirteen electron pairs.
- There are already three N-F bonds in the above drawn sketch. Now only 10 (13-3) electron pairs remains to mark on atoms.
- Usually, those remaining electron pairs should be started to mark on outside atoms (in this case, on fluorine atoms). So, we can mark lone pairs on fluorine atoms. Each fluorine atom will take 3 lone pairs and total of 9 electron pairs are marked on all 3 fluorine atoms.
- Now, only 1 lone pair is remaining and it can be marked on nitrogen atom.
Mark charges on atoms and reducing charges
There are no charges on nitrogen atom and fluorine atoms. Therefore, we do not need to worry about reducing charges on atoms to get the best stable structure. That means, we have found the lewis structure of NF3.
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