NF5 Lewis structure

NF₅ (nitrogen pentafluoride) has one nitrogen atom and five fluorine atoms.

In NF₅ Lewis structure, there are five single bonds around the nitrogen atom, with five fluorine atoms attached to it, and on each fluorine atom, there are three lone pairs.

Alternative method: Lewis structure of NF₅

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, nitrogen lies in group 15, and fluorine lies in group 17.

Hence, nitrogen has five valence electrons and fluorine has seven valence electrons.

Since NF₅ has one nitrogen atom and five fluorine atoms, so…

Valence electrons of one nitrogen atom = 5 × 1 = 5
Valence electrons of five fluorine atoms = 7 × 5 = 35

And the total valence electrons = 5 + 35 = 40

Learn how to find: Nitrogen valence electrons and Fluorine valence electrons

• Second, find the total electron pairs

We have a total of 40 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 40 ÷ 2 = 20

• Third, determine the central atom

We have to place the least electronegative atom at the center.

Since nitrogen is less electronegative than fluorine, assume that the central atom is nitrogen.

Therefore, place nitrogen in the center and fluorines on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 20 electron pairs. And five N — F bonds are already marked. So we have to only mark the remaining fifteen electron pairs as lone pairs on the sketch.

Also remember that both (nitrogen and oxygen) are the period 2 elements, so they can not keep more than 8 electrons in their last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are fluorines.

So for each fluorine, there are three lone pairs, and for nitrogen, there is zero lone pair because all fifteen electron pairs are over.

Mark the lone pairs on the sketch as follows:

Formal charge

Use the following formula to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

For nitrogen atom, formal charge = 5 – 0 – ½ (10) = 0

For each fluorine atom, formal charge = 7 – 6 – ½ (2) = 0

Here, both nitrogen and fluorine atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of NF₅ consists of a central nitrogen atom linked to five fluorine atoms through single covalent bonds. In this configuration, the nitrogen atom would theoretically utilize an expanded valence shell to form five bonding pairs with no remaining lone pairs. Within this layout, each fluorine atom reaches a stable octet by maintaining three lone pairs alongside its single shared bond. While this arrangement represents a theoretical state where the formal charge of every atom is zero, it is important to note that nitrogen lacks the available d-orbitals required to accommodate ten valence electrons. Consequently, this specific electronic distribution serves as the definitive and most accurate Lewis representation of nitrogen pentafluoride, even though the molecule is not stable under standard conditions.

Next: SiO Lewis structure