The Iodine atom Lewis structure is central I bonded; the central I has 4 electron domains (3 lone pairs), giving a tetrahedral electron-domain arrangement and a see text molecular geometry with a — bond angle. I is best described as sp3-hybridized, and Iodine atom is polar because the see text shape (and/or unequal terminal atoms) prevents cancellation of the bond dipoles.
Figure 1: Lewis Structure of Iodine atom (I)
| Chemical Formula | I |
| CAS Number | 14362-44-8 |
| Total Valence Electrons | 7 |
| Lewis Structure | central I bonded |
| Electron-Domain Geometry | tetrahedral |
| Molecular Geometry | see text |
| Hybridization Model | sp3 (central I) |
| Bond Angle | — |
| Polarity | Polar molecule |
Iodine atom is encountered as a reagent, intermediate or specialty chemical in inorganic, organometallic and materials synthesis. Confirm grade, purity and supplier documentation (SDS) before specifying for a process.
To draw the Iodine atom Lewis structure we first count the total valence electrons. I contains 7 (I); the net charge of 0 gives a total of 7 valence electrons to place.
The central atom is I. It is the least electronegative atom capable of forming multiple bonds and is surrounded by the more electronegative terminal atom(s); hydrogen, when present, always occupies a terminal position. Electronegativity considerations place the electron density toward the terminal atom(s).
Total valence electrons = 7 (I) = 7 electrons.
Place I at the center and connect each surrounding atom with a single bond, complete octets on the terminal atoms, and place any remaining electrons on the central atom. The resulting electron distribution is: central I bonded; 3 lone pairs on I and one unpaired electron on I.
Counting bonding and nonbonding electrons around I therefore satisfies the octet/expanded-octet requirement for the drawn structure.
VSEPR theory states that the 4 electron domains around I arrange to minimize mutual repulsion, giving an tetrahedral electron-domain geometry.
Because 3 of these domains are lone pair(s) — and lone pairs repel more strongly than bonding pairs — the observed molecular geometry is see text; the I bond angle is set to — rather than the ideal value for the electron-domain geometry.
A useful VSEPR approximation is: lone pair–lone pair repulsion > lone pair–bonding pair repulsion > bonding pair–bonding pair repulsion. With 3 lone pair(s) on I, the lone-pair domains occupy positions that minimize overall repulsion while pushing the bonding domains (and therefore the bonded atoms) closer together.
In the conventional localized-bond model, I uses sp3 hybrid orbitals to form the 4 equivalent electron-domain directions (0 bonding + 3 lone pair).
Formal charge on central I = V − N − ½B = 7 − 6 − ½×0 = 1. The nonzero formal charge is distributed by resonance / charge separation; the drawn structure is the lowest-energy contributor.
Iodine atom is polar. The see text shape prevents cancellation of the bond dipoles. The bond dipoles do not cancel, leaving a net molecular dipole, which strongly influences solvation behavior and intermolecular interactions.
The decisive structural fact is not simply that the individual bonds are polar; it is whether molecular symmetry allows their vector sum to vanish. In Iodine atom the see text arrangement prevents cancellation, so a permanent dipole remains.
Interpretation consistent with standard VSEPR / molecular-geometry references.This polarity profile underpins its behavior as a solvent, reactant or process intermediate; when sourcing, specify grade and container compatibility.
| Species | Formula | Central Atom | Electron Domains | Molecular Geometry | Polarity |
|---|---|---|---|---|---|
| Iodine atom | I | I | 4 | see text | Polar |
| Iodine trifluoride | IF3 | I | 5 | T-shaped | Polar |
| Iodine pentafluoride | IF5 | I | 6 | square pyramidal | Polar |
| Iodine heptafluoride | IF7 | I | 7 | pentagonal bipyramidal | Nonpolar |
| Iodine | I2 | I | 4 | linear (diatomic) | Nonpolar |
| Hydrogen iodide | HI | I | 4 | linear (diatomic) | Polar |
Iodine atom is polar. Its see text geometry (and/or unequal terminal atoms) stops the bond dipoles from cancelling.
central I bonded; 3 lone pairs on I and one unpaired electron on I. It uses all 7 valence electrons and the preferred structure carries a formal charge of 1 on the central atom.
The I angle is about —. Lone-pair repulsion compresses the angle from the ideal tetrahedral value.
The conventional model is sp3. Iodine atom has 4 electron domains around the central I.
The CAS number is 14362-44-8. PubChem (CID 5360629) and NIST identify this with I; use it to locate suppliers and database records.
Technical scope: Lewis structures, VSEPR and hybridization are model-based descriptions for chemical communication and structure prediction; actual molecular electronic structure is more accurately represented by molecular-orbital and quantum-chemical methods. Commercial grades vary substantially by supplier and intended use; CAS 14362-44-8 identifies the substance, not a universal purity specification.
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