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Fluorine is a chemical element; it has symbol F and atomic number 9. It is the lightest halogen [note 1] and exists at standard conditions as pale yellow diatomic gas. Fluorine is extremely reactive as it reacts with all other elements except for the light inert gases. It is highly toxic.
At 400 ppb, fluorine is estimated to be the 24th most common element in the universe. It is comparably rare for a light element (elements tend to be more common the lighter they are). All of the elements from atomic number 6 (carbon) to atomic number 12 (magnesium) are hundreds or thousands of times more common than fluorine except for 11 (sodium).
41 of the 118 known elements have names associated with, or specifically named for, places around the world or among astronomical objects. 32 of these have names tied to the places on Earth, and the other nine are named after to Solar System objects: helium for the Sun; tellurium for the Earth; selenium for the Moon; mercury (indirectly), uranium, neptunium and plutonium after their respective ...
The word "fluorine" derives from the Latin stem of the main source mineral, fluorite, which was first mentioned in 1529 by Georgius Agricola, the "father of mineralogy". He described fluorite as a flux—an additive that helps melt ores and slags during smelting. [1] [2] Fluorite stones were called schone flusse in the German of the time ...
Originally valued at six shillings, it was composed of 108 grains (6.99828 grams) of gold with a purity of 23 carats and 3 + 1 ⁄ 2 grains (or 23 + 7 ⁄ 8 carats) [7] [8] – and more recently (minted between 1849-1967 although circulating alongside the decimal ten pence coin until 1993 when it was withdrawn due to a resizing) relating to a ...
Fluorine, in the form of fluoride, is considered to be a micronutrient for human health, necessary to prevent dental cavities, and to promote healthy bone growth. [28] The tea plant (Camellia sinensis L.) is a known accumulator of fluorine compounds, released upon forming infusions such as the common beverage. The fluorine compounds decompose ...
The elements in group 13 are also capable of forming stable compounds with the halogens, usually with the formula MX 3 (where M is a boron-group element and X is a halogen.) [14] Fluorine, the first halogen, is able to form stable compounds with every element that has been tested (except neon and helium), [15] and the boron group is no exception.
The Codex Argenteus (literally: "Silver Book") was probably written for the Ostrogothic king Theodoric the Great, either at his royal seat in Ravenna, or in the Po valley or at Brescia; it was made as a special and impressive book written with gold and silver ink on high-quality thin vellum stained a regal purple, with an ornate treasure binding.