Mangan / Manganese (Mn)

Mangan je hemijski element atomskog broja 25. U periodnom sistemu elemenata predstavljen je simbolom Mn. Mangan je srebrnasto bijeli, tvrdi i lomljivi metal sličan željezu. Javlja se u četiri alotropske modifikacije. Lako je topljiv u razrijeđenim kiselinama uz razvoj vodonika . Reaktivan je kad je čist, pa reaguje s vodom i polako se otapa u njoj, a na površini oksidira u zraku, stvarajući smeđu prevlaku. Ona gori s kisikom svoje najstabilnije oksid, Mn3O4 . Elementarni mangan otkrio je švedski hemičar CW Scheele u Stockholmu 1774. godine, a iste godine izolovao ga je J. Gahn. Udio mangana u elementarnom sastavu Zemljine kore iznosi 0,085%, a vrlo je raširen u obliku spojeva.
Od ostalih mineralnih resursa pronađenih u morskom dnu, mangan ima najveću vrijednost koja se danas široko iskorištava. Prisutan je u malim količinama u biljnim i životinjskim ćelijama. Nalazi se u elementarnom stanju u meteoritima. Nalazi se u gotovo svim tlima, barem u tragovima.
Hemijski je sličan željezu i slijedi ga u rudi. Veće količine manganove rude nakupile su se na relativno malo mjesta na Zemlji.

Manganese is a chemical element of atomic number 25. Its symbol is Mn. Manganese is a silvery-white, hard and brittle metal similar to iron. It occurs in four allotropic modifications. It is easily soluble in dilute acids with the development of hydrogen. It is reactive when clean, so it reacts with water and slowly dissolves in it, oxidizing on the surface in the air, forming a brown coating. It burns with oxygen its most stable oxide, Mn 3 O 4. Elemental manganese was discovered by the Swedish chemist CW Scheele in Stockholm in 1774, and in the same year it was isolated by J. Gahn. The share of manganese in the elemental composition of the Earth's crust is 0.085%, and it is very widespread in the form of compounds.
Of the other mineral resources found in the seabed, manganese has the highest value that is widely exploited today.It is present in small amounts in plant and animal cells. It is found in the elemental state in meteorites. It is found in almost all soils, at least in traces.
It is chemically similar to iron and follows it in ore. Larger amounts of manganese ore have accumulated in relatively few places on Earth.