Element #53

Iodine

halogen solid Discovered 1811

126.904 Atomic Mass (u)

113.7 C Melting Point

184.3 C Boiling Point

4.933 g/cm3 Density

2.66 Electronegativity

[Kr] 4d10 5s2 5p5 Electron Config

5 Period

17 Group

📖 About Iodine

A dark purple-black solid that sublimes directly to violet vapor. Essential for thyroid hormone production and iodine deficiency is the leading preventable cause of intellectual disability worldwide, affecting 2 billion people. Radioactive iodine-131 released from nuclear accidents is particularly dangerous because the thyroid gland concentrates iodine.

🔧 Uses and Applications

Thyroid hormone production (essential nutrient)
Iodized salt (preventing deficiency)
Antiseptics (povidone-iodine)
Potassium iodide tablets (nuclear emergency protection)
Medical imaging (iodine contrast agents)

💡 Did You Know?

Fact: After the Chernobyl and Fukushima accidents, potassium iodide (KI) tablets were distributed to nearby populations. Flooding the thyroid with stable iodine prevents it from absorbing the radioactive iodine-131 released during a nuclear accident, reducing thyroid cancer risk.