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It may refer more specifically to the following manganese minerals: Birnessite, (Na,Ca) 0.5 (Mn IV,Mn III) 2 O 4 · 1.5 H 2 O; Buserite, MnO 2 ·nH 2 O; Hausmannite, Mn II Mn III 2 O 4; Manganite, Mn III O(OH)
2. Denotes the additive inverse and is read as minus, the negative of, or the opposite of; for example, –2. 3. Also used in place of \ for denoting the set-theoretic complement; see \ in § Set theory. × (multiplication sign) 1. In elementary arithmetic, denotes multiplication, and is read as times; for example, 3 × 2. 2.
The most stable are 53 Mn with a half-life of 3.7 million years, 54 Mn with a half-life of 312.2 days, and 52 Mn with a half-life of 5.591 days. All of the remaining radioactive isotopes have half-lives of less than three hours, and the majority of less than one minute.
Manganese(II,III) oxide is the chemical compound with formula Mn 3 O 4. Manganese is present in two oxidation states +2 and +3 and the formula is sometimes written as MnO·Mn 2 O 3. Mn 3 O 4 is found in nature as the mineral hausmannite.
The crystal structure of manganese(II) sulfide is similar to that of sodium chloride.. The pink color of MnS likely results from poor coupling between the lowest energy unoccupied Mn orbitals, resulting in discrete states rather than a delocalized band.
MnCO 3 → MnO + CO 2. This calcining process is conducted anaerobically, lest Mn 2 O 3 form. An alternative route, most interest for demonstration purposes, is the "oxalate method". Also applicable to the synthesis of ferrous oxide and stannous oxide, it entails heating in an oxygen-free atmosphere (often CO 2), hydrated manganese(II) oxalate: [9]
mno 2 + so 2 + h 2 o → mnso 4 (h 2 o) It can also be made by mixing potassium permanganate with sodium hydrogen sulfate and hydrogen peroxide . Manganese sulfate is a by-product of various industrially significant oxidations that use manganese dioxide, including the manufacture of hydroquinone and anisaldehyde .
Two forms are generally recognized, α-Mn 2 O 3 and γ-Mn 2 O 3, [10] although a high pressure form with the CaIrO 3 structure has been reported too. [ 11 ] α-Mn 2 O 3 has the cubic bixbyite structure, which is an example of a C-type rare earth sesquioxide ( Pearson symbol cI80, space group Ia 3 , #206).