As a solid, liquid, gas, or solution? Oh well.
Iodine typically has a shiny appearance, especially in its solid crystalline form. However, when iodine is in a gaseous state, it appears as a purple vapor.
Sublimation of iodine to iodine vapor is a physical change. It is a phase transition in which a substance goes directly from a solid to a gas without changing its chemical composition.
Iodine melting is a physical change, as it does not alter the chemical composition of the iodine. It simply changes from a solid to a liquid state due to the input of heat energy.
It is a physical change because no new substance is formed, it is the other form of iodine.
The appearance of iodine crystals: lustrous, metallic, gray.
When iodine dissolves in alcohol, it is a physical change because no new substances are formed. The iodine molecules are simply dispersed in the alcohol solution, but the chemical properties of iodine and alcohol remain the same.
When iodine is dissolved in alcohol, it forms a mixture of iodine and alcohol, which is physical.
Mixing bread with iodine solution to observe a color change is a physical change as it does not alter the chemical composition of the bread or the iodine solution. The color change occurs due to a physical interaction between the starch in the bread and the iodine molecules.
It is a physical change because the iodine is changing state from solid to gas without forming any new substances.
Grinding mercury or iodine would be a physical change - you are changing the shape but not the element. However, grinding mercury with iodine may be a chemical change if you end up with mercury iodide through a chemical reaction. Incidentally, I don't recommend actually trying this - mercury is a liquid at room temperature (it is also called quicksilver for this reason) and is very toxic to humans.
Iodine itself is a chemical element with a physical property, as it is a solid at room temperature and has a distinctive purple color. Its chemical properties involve its reactivity with other elements and compounds in chemical reactions.
Iodine is a solid at 20 degrees Celsius.