Iodine (I) — Element 53: Properties & Data | Aladdin Scientific
Iodine(I) — Element 53
Iodine (I) is a halogen with atomic number 53 and atomic mass 126.904. It has melting point 386.85 K (114 °C), boiling point 457.55 K (184 °C), density 4.93 g/cm³. It sits in group 17 and period 5 of the periodic table and was discovered in 1811.
Key facts
| Atomic mass | 126.9045 u |
|---|---|
| Electron configuration | [Kr]5s2 4d10 5p5 |
| Oxidation states | +7, +5, +1, -1 |
| Electronegativity (Pauling) | 2.66 |
| Atomic radius (van der Waals) | 198 pm |
| Ionization energy | 10.451 eV |
| Electron affinity | 3.059 eV |
| Melting point | 386.85 K |
| Boiling point | 457.55 K |
| Density | 4.93 g/cm³ |
| Standard state | Solid |
| Year discovered | 1811 |
Frequently asked questions
What is the electron configuration of iodine?
The ground-state electron configuration of iodine is [Kr]5s2 4d10 5p5.
What group and period is iodine in?
Iodine (I) is in group 17 and period 5 of the periodic table, classified as a halogen.
What is the melting point of iodine?
Iodine melts at 386.85 K (114 °C).
What is the standard state of iodine?
Iodine is a solid at standard temperature and pressure.
Related elements
About this data: property values compiled from IUPAC Standard Atomic Weights (2021), the NIST Atomic Spectra Database, and PubChem. Curated by the Aladdin Scientific technical team. Last reviewed: .