| Formula / Notation | I2 |
|---|---|
| CAS Number | 7553-56-2 |
| Molecular Weight | 253.81 |
| Melting Point | 113.7 |
| Boiling Point | 184.3 |
| Density | 4.93 |
| Solubility | 1.3 g/L at 20 C (slightly soluble) |
| Appearance | Lustrous, purple-black crystalline solid; violet vapour |
| Also Known As | I2, iodine element |
| Category | Elements |
What is Iodine?
Iodine is a lustrous purple-black non-metal halogen, atomic number 53. Sublimates readily to give a distinctive violet vapour. Essential trace element for thyroid hormone (thyroxine) synthesis. Iodine deficiency is the leading cause of preventable mental retardation worldwide.
Formula & Notation
IUPAC Name: Diiodine
Other Names / Synonyms: I2, iodine element
Properties & Characteristics
Physical Data
| Property | Value |
|---|---|
| Melting Point | 113.7 |
| Boiling Point | 184.3 |
| Density | 4.93 |
| Molecular Weight | 253.81 |
| Solubility | 1.3 g/L at 20 C (slightly soluble) |
| Appearance | Lustrous, purple-black crystalline solid; violet vapour |
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Iodine is a lustrous purple-black non-metal halogen, atomic number 53. Sublimates readily to give a distinctive violet vapour. Essential trace element for thyroid hormone (thyroxine) synthesis. Iodine deficiency is the leading cause of preventable mental retardation worldwide.
Antiseptics (iodine tincture, povidone-iodine). Thyroid function (I-131 for Graves disease and thyroid cancer treatment). Iodised salt (deficiency prevention). Starch test (turns blue-black with starch). Photography (silver iodide). Chemical synthesis. Iodine number (fat unsaturation).
Iodine vapour: irritant to eyes and respiratory tract. Skin contact: mild irritant, stains skin brown. Iodine poisoning: excessive intake harmful to thyroid. I-131: radioactive - accumulates in thyroid, causes thyroid cancer (used in nuclear accidents - KI tablets). Oxidising agent.
The formula or notation for Iodine is: I2