25
Mn
54.938
Manganese
Transition Metal
Group 7
Period 4
Block d
Manganese is a chemical element of the periodic table with chemical symbol Mn and atomic number 25 with an atomic weight of 54.938 u and is classed as transition metal and is part of group 7 (manganese group). Manganese is solid at room temperature.
Manganese in the periodic table
| Symbol | Mn |
| Atomic number | 25 |
| Group | 7 (Manganese group) |
| Period | 4 |
| Block | d |
| Classification | Transition Metal |
| Appearance | Silvery metallic |
| Color | Silver |
| Number of protons | 25 p+ |
| Number of neutrons | 30 n0 |
| Number of electrons | 25 e- |
From Wikipedia, the free encyclopediaManganese is a chemical element with symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in combination with iron, and in many minerals. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels.
Physical properties
| Phase at STP | Solid |
| Density | 7.21 g/cm3 |
| Atomic weight | 54.938 u |
Thermal properties
| Melting point | 1519 K 1245.85 °C 2274.53 °F |
| Boiling point | 2334 K 2060.85 °C 3741.53 °F |
| Heat of vaporization | 219.74 kJ/mol |
Atomic properties
| Electronegativity (Pauling Scale) | 1.55 |
| Electron affinity | -50 kJ/mol |
| Oxidation states | −3, −2, −1, 0, +1, +2, +3, +4, +5, +6, +7 (depending on the oxidation state, an acidic, basic, or amphoteric oxide) |
| Ionization energies |
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Electron configuration for manganese
Electron configuration Shorthand configuration | [Ar] 3d5 4s2 | ||||||||||||||||||||||
| Full configuration | 1s2 2s2 2p6 3s2 3p6 3d5 4s2 | ||||||||||||||||||||||
Electron configuration chart |
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| Electrons per shell | 2, 8, 13, 2 | ||||||||||||||||||||||
| Outer shell electrons | 2 | ||||||||||||||||||||||
| Valence electrons (incl. d) | 7 | ||||||||||||||||||||||
| Valency electrons | 2,4,7 | ||||||||||||||||||||||
| Bohr model | Figure: Shell diagram of Manganese (Mn) atom. | ||||||||||||||||||||||
Orbital Diagram |
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The history of Manganese
| Discovery | Carl Wilhelm Scheele (1774) |
| First isolation | Johann Gottlieb Gahn (1774) |
Discovery of manganese Manganese compounds were used by Egyptian and Roman glassmakers, either to add to, or remove, color from glass. Use as "glassmakers soap" continued through the Middle Ages until modern times and is evident in 14th-century glass from Venice. Because it was used in glassmaking, manganese dioxide was available for experiments by alchemists, the first chemists. Ignatius Gottfried Kaim (1770) and Johann Glauber (17th century) discovered that manganese dioxide could be converted to permanganate, a useful laboratory reagent. By the mid-18th century, the Swedish chemist Carl Wilhelm Scheele used manganese dioxide to produce chlorine. By the mid-18th century, Carl Wilhelm Scheele used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite (now known to be manganese dioxide) contained a new element. Johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon. | |
| Original word | magnes |
| Language of origin | Latin |
| Name source | Properties |
| Meaning | “Magnet” |
Naming The name either derives from the Latin word 'magnes', meaning magnet, or from ‘magnesia nigra’ indicating the black magnesium oxide in Latin. | |