Elements / 53
53I126.90
Iodine
Halogen · p-block · ring O · spoke 17
Iodine is element 53, a halogen. It sits on ring O (period 5) on spoke 17, the halogens. Follow that spoke toward the center and out again to find its chemical relatives.
Properties
| Density | 4.93 g/cm³ | Terrain → |
|---|---|---|
| Melting point | 387 K · 114 °C | Terrain → |
| Boiling point | 457 K · 184 °C | Terrain → |
| Electronegativity | 2.667th most electronegative of 100 | Terrain → |
| First ionization energy | 1,008 kJ/mol | Terrain → |
| Atomic weight | 126.904 u | Terrain → |
| Crustal abundance | 0.45 ppm | Terrain → |
| Discovered | 1811 | Terrain → |
Values from open reference data; see sources. "Terrain" opens that property as a 3D landscape across the whole spiral.
Two things you might not know
- Bernard Courtois found it in 1811 in seaweed ash, prized for saltpetre in the Napoleonic Wars, when acid sent up a cloud of violet vapour.
- The heaviest essential mineral nutrient, needed to make thyroid hormones; it is added to table salt and dabbed on skin as an antiseptic.
Checked against en.wikipedia.org.
Spoke 17: Halogens
Ring O (period 5)
Play with Iodine
Watch it fly into its seat, or raise the whole spiral into a landscape and see where it peaks.