Oxide

The unit cell of rutile. Ti(IV) centers are grey; oxide centers are red. Notice that oxide forms three bonds to titanium and titanium forms six bonds to oxide.

An oxide d/ is a chemical compound that contains at least one oxygen atom and one other element[1] in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– atom. Metal oxides thus typically contain an anion of oxygen in the oxidation state of −2. Most of the Earth's crust consists of solid oxides, the result of elements being oxidized by the oxygen in air or in water. Hydrocarbon combustion affords the two principal carbon oxides: carbon monoxide and carbon dioxide. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin skin of Al2O3 (called a passivation layer) that protects the foil from further corrosion.[2] Individual elements can often form multiple oxides, each containing different amounts of the element and oxygen. In some cases these are distinguished by specifying the number of atoms as in carbon monoxide and carbon dioxide, and in other cases by specifying the element's oxidation number, as in iron(II) oxide and iron(III) oxide. Certain elements can form many different oxides, such as those of nitrogen.

Formation

Due to its electronegativity, oxygen forms stable chemical bonds with almost all elements to give the corresponding oxides. Noble metals (such as gold or platinum) are prized because they resist direct chemical combination with oxygen, and substances like gold(III) oxide must be generated by indirect routes.

Two independent pathways for corrosion of elements are hydrolysis and oxidation by oxygen. The combination of water and oxygen is even more corrosive. Virtually all elements burn in an atmosphere of oxygen or an oxygen-rich environment. In the presence of water and oxygen (or simply air), some elements— sodium—react rapidly, to give the hydroxides. In part, for this reason, alkali and alkaline earth metals are not found in nature in their metallic, i.e., native, form. Cesium is so reactive with oxygen that it is used as a getter in vacuum tubes, and solutions of potassium and sodium, so-called NaK are used to deoxygenate and dehydrate some organic solvents. The surface of most metals consists of oxides and hydroxides in the presence of air. A well-known example is aluminium foil, which is coated with a thin film of aluminium oxide that passivates the metal, slowing further corrosion. The aluminum oxide layer can be built to greater thickness by the process of electrolytic anodizing. Though solid magnesium and aluminum react slowly with oxygen at STP—they, like most metals, burn in air, generating very high temperatures. Finely grained powders of most metals can be dangerously explosive in air. Consequently, they are often used in solid-fuel rockets.

Oxides, such as iron(III) oxide or rust, which consists of hydrated iron(III) oxides Fe2O3·nH2O and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3), form when oxygen combines with other elements

In dry oxygen, iron readily forms iron(II) oxide, but the formation of the hydrated ferric oxides, Fe2O3−x(OH)2x, that mainly comprise rust, typically requires oxygen and water. Free oxygen production by photosynthetic bacteria some 3.5 billion years ago precipitated iron out of solution in the oceans as Fe2O3 in the economically important iron ore hematite.

Other Languages
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العربية: أكسيد
asturianu: Óxidu
azərbaycanca: Oksidlər
বাংলা: অক্সাইড
беларуская: Аксіды
беларуская (тарашкевіца)‎: Аксыд
български: Оксид
bosanski: Oksid
català: Òxid
Чӑвашла: Оксидсем
čeština: Oxidy
chiShona: Oxides
dansk: Oxid
Deutsch: Oxide
eesti: Oksiidid
Ελληνικά: Οξείδιο
español: Óxido
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euskara: Oxido
فارسی: اکسید
français: Oxyde
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galego: Óxido
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italiano: Ossido
עברית: תחמוצת
ქართული: ოქსიდი
қазақша: Оксидтер
Latina: Oxidum
latviešu: Oksīdi
lietuvių: Oksidas
magyar: Oxidok
македонски: Оксид
മലയാളം: ഓക്സൈഡ്
Bahasa Melayu: Oksida
Nederlands: Oxide
日本語: 酸化物
Nordfriisk: Oksiid
norsk: Oksid
norsk nynorsk: Oksid
occitan: Oxid
oʻzbekcha/ўзбекча: Oksid
ਪੰਜਾਬੀ: ਆਕਸਾਈਡ
پنجابی: آکسائڈ
Plattdüütsch: Oxid
polski: Tlenki
português: Óxido
română: Oxid
Runa Simi: Muksi
русский: Оксиды
саха тыла: Оксид
Scots: Oxide
shqip: Oksidet
Simple English: Oxide
slovenčina: Oxid
slovenščina: Oksid
српски / srpski: Оксид
srpskohrvatski / српскохрватски: Oksid
suomi: Oksidi
svenska: Oxider
தமிழ்: ஆக்சைடு
Türkçe: Oksit
українська: Оксиди
Tiếng Việt: Oxit
文言: 氧化物
吴语: 氧化物
粵語: 氧化物
中文: 氧化物