* Solid State: In the solid state, iodine molecules (I₂) are tightly packed in a crystal lattice. The strong intermolecular forces (Van der Waals forces) hold these molecules in a fixed, ordered arrangement.
* Vibrational Motion: While the molecules are fixed in position, they can still vibrate around their equilibrium positions. This vibration involves the stretching and compression of the I-I bond within each iodine molecule.
* Limited Translational and Rotational Motion: Translational motion (movement from one point to another) and rotational motion are significantly restricted in solid iodine due to the strong intermolecular forces and the fixed positions of the molecules.
Therefore, the dominant motion in solid iodine is vibrational motion. This motion is responsible for the characteristic properties of solid iodine, such as its solid form at room temperature and its relatively low melting point.
