Iodine (I)

Iodine is a lustrous, purple-black nonmetallic solid that sublimes into a violet gas.

Core Principles & Analysis

• Bernard Courtois discovered iodine in 1811 when treating seaweed ash with sulfuric acid released violet vapors.
• The lustrous solid sublimes readily into a violet gas, and its name comes from the Greek word for violet.
• Iodine is essential for thyroid hormone synthesis, motivating iodized salt, and it is used in povidone-iodine antiseptics and X-ray contrast agents.

Specifications & Metrics

• NUM: 53
• SYMBOL: I
• CATEGORY: Reactive Nonmetal