Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 degrees Celsius, and boils to a violet gas at 184 degrees Celsius. The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek Ιώδης 'violet-coloured'. Iodine occurs in many oxidation states, including iodide (I−), iodate (IO− 3), and the various periodate anions. It is the least abundant of the stable halogens, being the sixty-first most abundant element. It is the heaviest essential mineral nutrient. Iodine is essential in the synthesis of thyroid hormones.[4] Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities.[5] The dominant producers of iodine today are Chile and Japan. Iodine and its compounds are primarily used in nutrition. Due to its high atomic number and ease of attachment to organic compounds, it has also found favour as a non-toxic radiocontrast material. Because of the specificity of its uptake by the human body, radioactive isotopes of iodine can also be used to treat thyroid cancer. Iodine is also used as a catalyst in the industrial production of acetic acid and some polymers. It is on the World Health Organization's List of Essential Medicines.[6]
Elven gymyk yw iodin, niver 53 y'n Vosen Beriodek. Y furvell gymyk yw I. An hanow a dheu dhyworth an ger Greka iodes, ow styrya purpur. Hanow an elven yw iodin, hag a eksist avel molekulen I2. Kevys yw avel gwrysow du, gass purpur ha teudhans melynik. Pan gaffo iodin elektron, ev a furv ion, iodid, skrifys avel I-. Essensek yw iodin dhe lies eghen, ow komprehendya tus, mes nyns yw essensek dhe blansow. Gass iodin a serr an lagasow ha skevens. Gwenonek yw an elven, mar vyghan avel 2g a alsa ladha. Yn fordh aral, salow yw iodidow herwydh usadow. Iodin a greun y'n gwagren thyroydek y'n korf denel. Yma edhomm dhe'n korf a iodin rag tevyans, displegyans ha bewnans hir. Re nebes anodho a wra kawsya nebes klevesow, rag ensampel, hwedh lonk (goitre) ha hypothyroydyeth. Pennfenten posek a iodin yw leth ha boos mor. Yn 1820 usys veu iodin avel medhegneth rag an kynsa prys gan Dr Jean-François Coindet (1774-1834). Ev a wrug usya teudhans a iodin a potassiom iodid yn alkohol dhe dhyghtya hwedh lonk. Y'n gwettha prys,yth esa kudynnow gans drog torr. Mes usys veu awosa dhe dhyghtya goliow ygor, hag yn 1930 dyskys veu dhe geworra iodid dhe holan kemmyn. Diskudhys veu iodin yn 1811, awos an Breselyow Napoleonek. An Morlu Bretennek a omsettyas a-dro dhe Bow Frynk, dhe lettya provyans polter gonn. Bernard Courtois, kymegydh neb a driga ogas dhe Baris, a usya gommon dhe wul solpyter (pennfenten potassiom), rann a bolter gonn. Unn jydh, ev a geworras trenken sulfurik dhe'n godhes. Ev y's teva marth pan welas mog purpur ow sevel dhyworth an kowdarn. Ev a ros samplow dhe dhew goweth neb veu kymegydhyon, Charles-Bernard Desormes ha Nicolas Clément. I a wrug moy a hwithrans, hag yn 1813 prevys veu eksistyans iodin gan Joseph Gay-Lussac ha Humphrey Davy. Gay-Lussac a'y henwis. Askorrys yw a-dro dhe 13,000 tonnas an vledhen, dre vras yn Chile (40%) ha Nihon (30%) dhyworth hyli. Usys yw y'n diwysyans medhegieth, boos enevales, liwyow hag ynkys. Y hyllir devnydhya arghans iodid dhe hasa komol ha kawsya glaw. Iodin a eksist avel gwrysow du splann. Ev a wra segh-ethenna orth dommhe dhe furvya gass purpur. Y boos atomek yw 126.90, y boynt teudhi yw 114°C ha'y boynt bryjyon 184°C. Y dhosedh yw 4.9kg an liter.langbot langbot