NI3 Lewis Structure & Characteristics: 17 Complete Facts

NI3 Lewis structure refers to the electronic skeleton of the compound, NI3. Here the electrons are represented by dots. Let us take a brief idea on NI3 Lewis structure.

NI3 Lewis structure is reliable in imposing a well-defined electronic structure of the compound. It can evaluate the number of electrons engaged from the side of both Nitrogen and Iodine in the formation of NI3 or Nitrogen triiodide. The process of internal bonding is also described by the Lewis structure.

NI3 Lewis structure represents several facts about the shape, internal bonding, angle, the rule behind the electronic reaction and others. Let us describe the interesting facts with chemical justifications throughout this article.

How to draw NI3 Lewis structure?

Drawing NI3 Lewis structure can be preceded through some common steps. Those steps, chemically related with bond creation are being discussed below.

Step 1: Valence electron calculation

Calculating the number of valence electrons, the most fundamental and significant step for the drawing. As Lewis structure is all about electronic expression of a compound, it is required to calculate the exact number of electrons present internally in the compound.

Step 2: Count of required electrons in Nitrogen and Iodine atoms

Every element in periodic table need to fill octet state to get ultimate stability. After calculating the valence electrons, we can identify the deficiency or amplitude of electrons in the elements. Depending on the requirements, electron share of transfer is discovered in second step.

Step 3: Centre atom selection

Selecting a suitable centre atom is much-needed factor to sketch the Lewis structure. The least electronegative atom always gets first priority to be in the centre of design. In NI3, Iodine is more electronegative than Nitrogen therefore; Nitrogen achieves centre position in the compound.

Step 4: Electron dot representation to refer bonds

Representation of electron dots is the valuable a factor for analysing the bonds between two different atoms. Putting two dots as two electrons in between the elements refers to the connection between elements with sigma bond.

Step 5: Stability checking for the final electron of NI3

After expressing the bonds in the compounds, the last function would be stability check.  For any compound, it is important to check the overall structure that if it has followed the rules before being engaged in electron sharing process. This information confirms the stability of the NI3 also.

NI3 Lewis structure resonance

Resonance happens due to the presence of π bonds or negative charge. It embeds similar kind of alternative structure of the compounds. Let us find if it works for NI3 or not.

NI3 Lewis structure has no resonance due to an insignificant factor.  As in NI3, there are no π bonds in the internal structure or it does not possess any positive or negative charge as well. Having alternative resonance structure is impossible for NI3.

NI3 Lewis structure shape

Shape is the outermost feature that gives proper outlook of a compound. Lewis structure holds to discover the shape of compounds. Let us find the shape of NI3 below.

NI3 Lewis structure is shaped as Trigonal pyramidal. The presences of lone pair on Nitrogen, the central atom brings forth a bent shape to the compound. An asymmetric design of NI3 can be found from the Lewis structure of NI3. Electronic geometry of NI3 is Tetrahedral.

ni3 lewis structure
NI3 Lewis structure from Wikipedia

According to VSEPR (Valence Shell Electron Pair Repulsion), theory exhibits the idea of effect of lone pairs on shape of the compounds.  An external tension is created by the lone pair of Nitrogen in NI3 that affects the ideal shape of the compound.

NI3 Lewis structure formal charge

Formal charge displays the fact of electron contribution on the bonding by each element. Let us calculate the formal charge of NI3 by calculating the same for individuals.

A specific formula is there to calculate the formal charge of compounds. The formula is Formal charge = Number of valence electrons – Number of nonbonding valence electrons – (Bonding electrons/2)

The calculation is broadly outlined through the table below:

Elements &
Number of
Number of
Valence Electrons
Contribution in bonding
(Bonding electrons/2)
1. N523/2(5-2-3/2) = 0.5
2. I1761/2(7-6-1/2) = 0.5
3. I2761/2(7-6-1/2) = 0.5
4. I3761/2(7-6-1/2) = 0.5
5. NI3[0.5-(0.5-0.5-0.5)] = 0
Formal Charge calculation of NI3 Lewis structure

NI3 Lewis structure octet rule

Octet rule states that each element in periodic table wants to fill octet state to get stability like noble gases. Let us identify how NI3 satisfies octet rule.

NI3 Lewis structure octet rule drives both N and I to fill their last shell with 8 electrons. It helps the atoms to satisfy octet state with high stability in periodic table. The nearest noble gas of N and I atoms are Helium and Xenon, both the element tends to create same electronic configuration as them.

In the case of stabilising the position in periodic table Both Nitrogen and iodine shared electron by making eight electrons in last energy level. Nitrogen shares three electrons with three similar Iodine atoms by borrowing one electron from each of the Iodine atoms and creates bonds with each other.

NI3 Lewis structure lone pairs

Lone pair detection in the compounds is a significant factor that helps to identify internal tension inside the compounds. Let us calculate how many lone pairs are there in NI3.

NI3 Lewis structure holds total 10 lone pairs. After making bonds, Nitrogen is left with one lone pair. Each of the Iodine atoms holds three lone pairs, which adds total 9 lone pairs in the Lewis structure. Lone pairs play a huge role on the internal design of the compounds.

According to VSEPR theory, Lone pair-lone pair repulsion is one of the biggest factors in the internal body of compounds, which implements effects on the shape and bond angle.

NI3 valence electrons

The number of valence electrons is the most valuable information about elements that activates the sketching of compounds. Let us calculate the number of valence electron in NI3.

  • The number of valence electrons in Nitrogen = 5
  • The number of valence electrons in each Iodine atom = 7
  • The total number of valence electrons in 3 Iodine atoms = (3*7) = 21
  • Total number of valence electrons in NI3 = (5+21) = 26

NI3 bond angle

Bond angle is the fact that is needed to identify for making an idea about the capacity of holding bonds in the elements. Let us recognise the bond angle of NI3.

NI3 bond angle is 107.1º. This is not the ideal bond angle of Nitrogen triiodide in accordance with its shape, molecular geometry and hybridisation. The ideal bond angle should be 109.5º. Therefore, it can be identified that the compound is slightly deviated from the ideal angle.

This above-mentioned deviation happens due to the presence of lone pair on Nitrogen. This lone pair creates repulsion between the electron pairs, which generally gives a bent shape to the compound and reduces its bond angle from the ideal one.

NI3 hybridization

Hybridisation refers to the mixing of orbitals for different elements after making bonds with each other. Let us point out the mixed orbital structure of NI3.

NI3 is a sp3-hybridised molecule. Steric numbers of compounds help to pick out the hybridisation structure. The steric number of NI3 is found as four which denotes the hybridisation as sp3.  However, according to VSEPR chart, the ideal hybridisation of tetrahedral electronic geometry is sp3.

Steric number of NI3 is calculated by adding the number of bonded atoms on Nitrogen and the lone of lone pair on the same. Number if bonded atom here is three and lone pair is one. These make the steric number 4 in total and indicate one electron pair in s orbital and others on three p orbitals.

Is NI3 solid?

Solid is the common state of many compounds in chemistry. Let us take a justified identification about the state of Nitrogen triiodide in this section.

NI3 is a solid compound. This compound naturally appears in solid state with dark colour. This pyramidal compound is formed by a reaction between Iodine and ammonia and both the reactants are solid in state. These element gives out dark red compound named as Nitrogen triiodide.

Why and How NI3 is solid?

NI3 is solid due to the strong electrostatic force inside the compounds. Generally, compounds gain solid state by the effect of internal strength. Impact geometry of NI3 proofs its solid state with dark colour. However, after explosion, that compound makes dark purple vapour of Iodine.

Is NI3 soluble in water?

Solubility is the factor that varies compound to compound by the internal effects of elements on bonds. This would fun to check solubility of NI3.

NI3 is insoluble in water. This insolubility refers to its solid state. This molecule is an exceptional compound in the series of NF3, NCl3, NBr3 and NI3. Insolubility of NI3 stands fir the fact that says this compound does not decomposes in water easily.

Why and how NI3 is insoluble in water?

NI3 is insoluble in water because of the unnecessary collision between Iodine atoms and steric hindrance. Generally, halide molecules are noticed to be soluble in water. NI3 is exception of this fact. NI3 is insoluble in water by the internal repulsion between non-bonded Iodine atoms.

Is NI3 polar or nonpolar?

Polarity and non-polarity is the fact that defines internal optimistic functions of the compounds. Let us identify if NI3 is polar or non-polar.

NI3 is a polar compound. Its polarity comes from an asymmetric standardisation of structure. The bent shape of the compound works behind the creation of specific Dipole moment around the terminals of Nitrogen triiodide.

Why is NI3 polar?

NI3 is polar due to the internal effect created by the lone pair of Nitrogen. The bent shape of NI3 distant the compound from being symmetric notation in chemistry. An unequal distribution of charge throughout the elements is by the lone pair, which does not let the compound to cancel out its dipole moment.

How does NI3 polar?

NI3 is polar by the effect of three different factors. The factors are electronegativity, shape and dipole moment. Though different between electronegativity between N and I atoms is little and create non-polar bonds, the lone pair on N makes the overall compound polar.

Is NI3 a molecular compound?

Molecular appearance depends on the neutrality of compounds where they do not hold any negative or positive charge.  Let us find if NI3 is molecular or not below.

NI3 is a molecular compound.  Specific molecular geometry of Nitrogen triiodide refers to its neutral formation.  NI3 is naturally molecular which follows the definite rules of forming a molecule in chemistry.

ni3 lewis structure
NI3 Chain-like geometry from Wikipedia

Why and how NI3 is molecule?

NI3 is molecule because it takes appearance as a neutral compound. It does not hold deficiency of excessiveness of electrons in side. The way it can be called molecule is defined as the electronic reaction between two different types of atoms that make molecule.

Is NI3 an acid or base?

According to Lewis, acidity refers to electron acceptance capability and basicity depends on capability of electron donation.  Let us find for which factor Ni3 is capable.

NI3 can be considered as an acid and least basic. This fact has been identified by discovering the matches between ideal definition of Lewis acidity or basicity and capability of Ni3 in accepting or donating electrons.

Why NI3 is an acid?

NI3 is an acid due to its high capability of accepting electron. Iodine atoms are capable of accepting electrons as an important part of NI3.  The compound is not capable of giving up electrons unless forced by some external effect. This factor makes the overall compound least basic.

How NI3 is an acid?

NI3 is an acid by the electron accepting ability of Iodine. Iodine has void space in its d orbitals where it can easily give place to electrons. In this way, the overall compound satisfies the condition of being a Lewis acid.

Is NI3 an electrolyte?

Electrolytes are capable of conducting electricity in molten state or break into ions readily. Let us identify if NI3 follows any of these criteria below.

NI3 is a strong electrolyte. After having several, exceptionality this compound can show electrolytic nature without following the aspects, an electrolyte should possess. The reason of calling NI3 an electrolyte is given below.

Why and how NI3 is a strong electrolyte?

NI3 is a strong electrolyte because its explosive nature. Even after being insoluble in water, it has high capacity in breaking into ions. As a huge difference in size between N and I atoms, N-I bond in Ni3 is weak and it readily breaks into Iodide ions. Hence, it shows electrolytic property in it.

Is NI3 a salt?

Salt holds some special characteristics for being called salt like high solubility in water. Let us identify if NI3 holds such characteristics and called salt or not.

NI3 cannot be called a salt. A salt should always be crystalline or in a form of crystalline powder in white colour.  Besides, salt should be soluble in water. Most of the time salts are found as colourless crystals like ice cubes or in a transparent design.

Why and how NI3 is not a salt?

NI3 is a not a salt because it is clear that the compound is not soluble in water. It definitely stays neutral in nature but the crystal of NI3 is dark red in colour and not transparent as well. Toxicity and formation from nuclear explosion of Nitrogen triiodide distinguishes it from salts.

Is NI3 ionic or covalent?

Ionic or covalent nature of compounds abbreviates the formation process of bonds between the elements. Let us find which kind of bond NI3 is possessing with chemical overview.

NI3 is covalent. NI3 is formed by the cooperation between valence electrons of Nitrogen and Iodine atoms. Covalence is the key factor that works behind the bonding between Nitrogen and Iodine atoms. Covalence characteristics give bond strength to the elements by adopting chemical stability.

Why and how NI3 is covalent?

NI3 is covalent due to the supportive nature of Nitrogen and Iodine. Both the element has electron deficiency in related with the octet state. Both element fills octet and get stability by sharing valence electrons with each other. In this way they make covalent bonds.

Is NI3 stable?

Stability of NI3 is a great fact that gives knowledge about the existence of NI3 as an explosive matter in nature. Let us find if NI3 is stable or not.

NI3 is an unstable compound. As we know this is highly explosive, that can defined by the structure and formation category with a broad description. Size of the participative elements in a compound formation always effects on the stability of compounds. This factor matters in the case of instability of NI3.

Why and how NI3 is unstable?

NI3 is unstable because the size difference between Nitrogen and Iodine atoms is quite high. Nitrogen is a tiny atom that gets the centre position in NI3 and bears the burden of three large Iodine atom that creates steric strain.  It becomes difficult NI3 to manage the steric effect that makes it unstable.


This article has descried the exceptional characteristics of NI3, which are discovered from the NI3 Lewis structure. This electronic structure has significantly brought forth information about bent shape and deviation from ideal bond angle of the compound by evaluating its specialty.

Sarnali Mukherjee

Hi.....I am Sarnali Mukherjee, a graduate from the University of Calcutta. I love to teach and share knowledge on chemistry. I have gradually gained interest in article writing since one year ago. I would love to acquire more knowledge on my subject in the future. Let's connect through LinkedIn:

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