elements · 53 / 118 · All 118

Iodine

Z: 53
Mass: 126.904
Lifeforce: Water
In the body: thyroid

Fifteen to twenty milligrams in the whole body, most of it in the thyroid. And yet this trace sets the pace of every cell: without iodine the hormone of metabolism never forms at all.

A still bowl on a stone catches rain, overflows and waters young sprouts. — Plate · Water Water grasps at nothing. It *receives*, until the bowl overflows and feeds.

Heavy enough that it is made primarily in neutron-star collisions. Every iodine atom in your thyroid is older than the Sun.

Lab note · Builds thyroxine, the hormone that regulates metabolism. Iodine deficiency once caused widespread cretinism; iodized salt ended it.

Tool · Cosmic origin

Where your atoms come from

I · Neutron stars

Forged in the collision of neutron stars, among the rarest events in the cosmos. Older than the Sun.

8 of the 118 elements share this origin.

Choose a stage: click, or arrow keys. · Cosmic nucleosynthesis · current standard model

Tool · Periodic table

Your place in the system

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