What is the Lewis structure of iodomethane, CH3I? Atomic number of Iodine is 53. H H H-C-H I-C-I H Option 3 H H-C-I H
The Correct Answer and Explanation is:
The correct Lewis structure for iodomethane (CH₃I) is Option 3 in the image.
Explanation
Iodomethane, also known as methyl iodide, has the molecular formula CH₃I. The molecule consists of one carbon (C) atom, three hydrogen (H) atoms, and one iodine (I) atom. To determine the correct Lewis structure, it is essential to follow the standard procedure of assigning electrons and bonds according to the octet rule and known valencies of each element.
Carbon has four valence electrons and typically forms four covalent bonds. Hydrogen has one valence electron and forms only one bond. Iodine, a halogen, has seven valence electrons and typically forms one bond, completing its octet with three lone pairs.
In CH₃I, the central atom is carbon. It bonds to three hydrogen atoms through single covalent bonds, each sharing one electron. The fourth bond on the carbon goes to the iodine atom. This single C–I bond satisfies carbon’s need for four bonds.
Iodine, with seven valence electrons, uses one to bond with carbon. The remaining six electrons are arranged as three lone pairs on the iodine atom. This satisfies the octet rule for iodine (one bonding pair + three lone pairs = eight electrons total).
Option 3 in the image correctly shows:
- Carbon at the center with four single bonds: three to hydrogen and one to iodine.
- Iodine with three lone pairs.
- No extra or missing bonds.
- Hydrogen atoms with no lone pairs, each forming a single bond.
Incorrect options fail in one or more of these areas. For instance, Option 1 lacks the iodine atom, Option 2 shows iodine twice (which is not chemically accurate), and Option 4 places iodine in an incorrect position relative to bonding.
Thus, Option 3 correctly represents the Lewis structure of iodomethane, CH₃I.
