Mn
Manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It has a standard atomic weight of 54.938, sits in period 4 and group 7, and is classified as a transition metal.
Properties
| Symbol | Mn |
|---|---|
| Atomic number | 25 |
| Standard atomic weight | 54.938 |
| Category | Transition metal |
| Group | 7 |
| Period | 4 |
| Electron configuration | [Ar] 3d5 4s2 |
| Outer-shell electrons | 2 |
The figure of 54.938 is a standard atomic weight.
Compounds containing manganese
2 of the compounds in this reference contain Mn, listed by the fraction of their mass it makes up.
| Compound | Formula | Atoms | % by mass |
|---|---|---|---|
| manganese dioxide | MnO2 | 1 | 63.2% |
| potassium permanganate | KMnO4 | 1 | 34.8% |
Calculate with manganese
- Molar mass of any formula containing it
- Electron configuration, including ions
- Effective nuclear charge by Slater's rules
- Average atomic mass from isotope abundances
Group 7
Atomic weights are the IUPAC 2021 standard values, abridged to the conventional five significant figures. Group, period, category and electron configuration are derived from the atomic number rather than stored, so they cannot drift out of step with it.