Iodine sublimes for the same reasons that all solids do: because it has some equilibrium vapor pressure an normal conditions. Now, the value of that pressure varies greatly in different solids. For many of them, it is so extremely low that for all practical reasons it can be considered non-existent.

Does iodine undergo sublimation?

Either the diagram was wrong, or iodine does not undergo sublimation at standard pressure. (A phase diagram of iodine is shown below). ... The iodine formed a splatter pattern, indicative of the presence of a liquid. The phase diagram was correct — and I was wrong.

How do you sublime iodine?

Place 2 grams of Iodine in a 500 mL Erlenmeyer flask, and set a watch glass with ice over the mouth of the flask. Place the flask on a hot plate, and turn on the hot plate so the flask is heated slowly. Purple Iodine vapor will be formed, and solid Iodine crystals should form on the bottom of the watch glass.