Iodine

Iodine is a chemical element with the symbol I and atomic number 53. It is a non-metal that belongs to the halogen group of elements. Iodine is a lustrous, purple-black solid at room temperature and is one of the rare elements that can be found in a solid state as well as a gas. Here are some key points to understand about iodine:

Properties of Iodine

Physical Properties: Iodine has a characteristic purple color and a metallic luster. It sublimes (turns directly from a solid to a gas) when heated, and forms purple vapors.

Chemical Properties: Iodine is less reactive than other halogens such as fluorine, chlorine, and bromine. It reacts with metals to form iodides, and with non-metals to form compounds known as iodides and iodates.

Uses of Iodine

Iodine has several important uses:

Medical Applications: Iodine is used in the production of medicines and disinfectants. It is also an essential element for the human body, as it is a crucial component of the thyroid hormones.
Industrial Applications: Iodine is used in the production of dyes, photographic chemicals, and certain polymers.
Nutritional Supplements: Iodine is added to table salt to prevent iodine deficiency, which can lead to thyroid disorders and other health issues.

Study Guide

Here are some key points to focus on when studying iodine:

Understand the physical and chemical properties of iodine, including its appearance, state at room temperature, and reactivity with other elements.
Learn about the uses of iodine in various fields, including medicine, industry, and nutrition.
Explore the role of iodine in the human body and its importance for thyroid function.
Practice identifying iodine-based compounds and understanding their chemical properties.
Review the methods of obtaining iodine from natural sources and industrial processes.