Fe2O3 can be obtained in various polymorphs. In the main ones, α and γ, iron adopts octahedral coordination geometry. That is, each Fe center is bound to six oxygen ligands.Alpha phase α-Fe2O3 has ...
Potassium oxide is produced from the reaction of oxygen and potassium; this reaction affords potassium peroxide, K2O2. Treatment of the peroxide with potassium produces the oxide:K2O2 + 2 K → 2 K2OAl ...
Sodium oxide is produced by the reaction of sodium with sodium hydroxide, sodium peroxide, or sodium nitrite:2 NaOH + 2 Na → 2 Na2O + H2Na2O2 + 2 Na → 2 Na2O2 NaNO2 + 6 Na → 4 Na2O + N2Most of thes ...
Iron(II) oxide adopts the cubic, rock salt structure, where iron atoms are octahedrally coordinated by oxygen atoms and the oxygen atoms octahedrally coordinated by iron atoms. The non-stoichiometry o ...
Magnesium oxide is produced by the calcination of magnesium carbonate or magnesium hydroxide or by the treatment of magnesium chloride with lime followed by heat.Applications A refractory material is ...
Calcium oxide is usually made by the thermal decomposition of materials such as limestone, or seashells, that contain calcium carbonate (CaCO3; mineral calcite) in a lime kiln. This is accomplished by ...
Corundum is the most common naturally occurring crystalline form of aluminium oxide. Rubies and sapphires are gem-quality forms of corundum, which owe their characteristic colors to trace impurities. ...
Silicon dioxide is obtained by mining and purification of the resulting mineral. Quartz comprises more than 10% by mass of the earth's crust. Commercial silicon dioxide is also produced, almost always ...
Two major methods are employed to produce 100 million tonnes of O2 extracted from air for industrial uses annually. The most common method is to fractionally distill liquefied air into its various com ...
At standard temperature and pressure, oxygen is a colorless, odorless gas with the molecular formula O2, in which the two oxygen atoms are chemically bonded to each other with a spin triplet electron ...
On April 7, 1795, the gram was decreed in France to be "the absolute weight of a volume of pure water equal to the cube of the hundredth part of the metre, and at the temperature of melting ice." The ...
The Earth formed from the same cloud of matter that formed the Sun, but the planets acquired different compositions during the formation and evolution of the solar system. In turn, the natural history ...
Peru covers 1,285,216 km2 (496,225 sq mi) of western South America. It borders Ecuador and Colombia to the north, Brazil to the east, Bolivia to the southeast, Chile to the south, and the Pacific Ocea ...
The Mariana Trench is named for the nearby Mariana Islands (in turn named Las Marianas in honor of Spanish Queen Mariana of Austria, widow of Philip IV of Spain). The islands are part of the island ar ...
The summit was first reached in July 1932 by a joint German–Austrian expedition. The north peak (Huascarán Norte) had previously been climbed in 1908 by a U.S. expedition that included Annie Smith P ...
