Final answer:
Sodium thiosulfate and lemon juice effectively remove iodine stains because they can reduce the iodine through a chemical reaction.
Step-by-step explanation:
Lemon juice or a 10% solution of sodium thiosulfate can effectively be used to remove the stain caused by iodine. This is because iodine, which is a halogen, works by oxidizing cellular components and can cause staining. The reducing properties of sodium thiosulfate and the acidic nature of lemon juice help to reduce the iodine, thus removing the stain it causes on fabrics or skin.