| Group | 7 | Melting point | 1246 oC, 2274.8 oF, 1519.15 K |
| Period | 4 | Boiling point | 2061 oC, 3741.8 oF, 2334.15 K |
| Block | d | Density (kg m-3) | 7473 |
| Atomic number | 25 | Relative atomic mass | 54.938 |
| State at room temperature | Solid | Key isotopes | 55Mn |
| Electron configuration | [Ar] 3d54s2 | CAS number | 7439-96-5 |
| ChemSpider ID | 22372 | ChemSpider is a free chemical structure database | |
Image explanation
The image reflects the origin of name of the element in the form of an antique electro magnet and its importance as a food supplement to grazing animals.
Appearance
A hard, brittle, silvery metal used to harden steel. It is an essential element for all living things. Certain soils are deficient in it, and so it is added to some fertilisers and given as a food supplement to grazing animals. The average human body contains about 12 milligrammes and takes in about 4 milligrammes per day from such foods as nuts, bran, wholegrain cereals, tea and parsley.
Uses
Manganese is used to form many important alloys. It gives steel a hard yet pliant quality, and with aluminium and antimony it forms highly ferromagnetic alloys. Manganese(IV) oxide is used as a depolariser in dry cells, and to decolourise glass - which is coloured green by iron impurities. Manganese(II) oxide is a powerful oxidising agent and is used in quantitative analysis.
Biological role
Manganese is an essential element. Without it, bones grow spongier and break more easily. It activates many enzymes and may be essential for utilization of vitamin B. . Certain soils are deficient in it, and so it is added to some fertilisers and given as a food supplement to grazing animals. The average human body contains about 12 milligrammes and takes in about 4 milligrammes per day from such foods as nuts, bran, wholegrain cereals, tea and parsley. Exposure to manganese dust, fumes and compounds is to be avoided as it is a suspected carcinogen.
Natural abundance
Manganese minerals are widely distributed with pyrolusite and rhodochrosite being the most common. Manganese nodules have been found on the floor of the oceans. These nodules contain about 24% manganese together with smaller amounts of many other elements.
| Atomic radius, non-bonded (Å) | 2.050 | Covalent radius (Å) | 1.29 |
| Electron affinity (kJ mol-1) | Not stable |
Electronegativity (Pauling scale) |
1.550 |
|
Ionisation energies (kJ mol-1) |
1st
717.273
2nd
1509.029
3rd
3248.466
4th
4940.045
5th
6985.533
6th
9223.991
7th
11501.332
8th
18766.383
|
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| Common oxidation states | 7, 6, 4, 3, 2, 0, -1 | ||||
| Isotopes | Isotope | Atomic mass | Natural abundance (%) | Half life | Mode of decay |
| 55Mn | 54.938 | 100 | - | - | |
|
Molar heat capacity (J mol-1 K-1) |
26.32 | Young's modulus (GPa) | Unknown | |||||||||||
| Shear modulus (GPa) | Unknown | Bulk modulus (GPa) | 118 | |||||||||||
| Vapour pressure | ||||||||||||||
| Temperature (K) |
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| Pressure (Pa) |
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Images: Visual Elements © Murray Robertson 2011
Mining and Sourcing data: British Geological Survey – natural environment research council.
Text: John Emsley Nature’s Building Blocks: An A-Z Guide to the Elements, Oxford University Press, 2nd Edition, 2011.
Data: CRC Handbook of Chemistry and Physics, CRC Press, 92nd Edition, 2011.
G. W. C. Kaye and T. H. Laby Tables of Physical and Chemical Constants, Longman, 16th Edition, 1995.
Members of the RSC can access these books through our library.
Mining and Sourcing data: British Geological Survey – natural environment research council.
Text: John Emsley Nature’s Building Blocks: An A-Z Guide to the Elements, Oxford University Press, 2nd Edition, 2011.
Data: CRC Handbook of Chemistry and Physics, CRC Press, 92nd Edition, 2011.
G. W. C. Kaye and T. H. Laby Tables of Physical and Chemical Constants, Longman, 16th Edition, 1995.
Members of the RSC can access these books through our library.
