Manganese (Mn)
Manganese is element 25, a transition metal in group 7, period 4. A neutral atom has 25 protons, 30 neutrons and 25 electrons, 2 of them valence electrons.
Transition metal- Atomic number
- 25
- Atomic mass
- 54.938 u
- Valence electrons
- 2*
- Protons · neutrons
- 25 · 30
- Electrons per shell
- 2, 8, 13, 2
- At room temperature
- solid
Bohr model of manganese
The Bohr model draws manganese as a nucleus of 25 protons and 30 neutrons, with its 25 electrons on 4 circular shells: 2 in shell 1, 8 in shell 2, 13 in shell 3, 2 in shell 4. Press Build the atom to watch the shells fill from the inside out. The outer ring (the N shell) is dashed: the electrons there are the ones that take part in chemistry.
Real electrons don't travel in neat circles. They live in fuzzy orbitals, shown below, but the Bohr picture is the quickest way to count shells and valence electrons.
Electron configuration of manganese
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵
Short form (noble gas notation): [Ar] 4s² 3d⁵. The [Ar] stands for the electrons of argon, the noble gas before it.
How many valence electrons does manganese have?
Manganese has 2 valence electrons.
Manganese is a transition metal, so its valence electrons are less clear-cut than for main-group elements. It has 2 electrons in its outermost shell (shell 4), and electrons in its inner d subshell can also take part in bonding.
Protons, neutrons and electrons
| Protons | 25 | equal to the atomic number |
|---|---|---|
| Electrons | 25 | equal to the protons in a neutral atom |
| Neutrons | 30 | mass number 55 − 25 protons |
Atoms of the same element can have different numbers of neutrons (isotopes). The count above uses the rounded atomic mass, the way it's taught in class.
Manganese properties
| Symbol | Mn |
|---|---|
| Category | Transition metal |
| Group · period · block | 7 · 4 · d |
| Atomic mass | 54.938 u |
| State at 25 °C | solid |
| Melting point | 1,519 K (1,250 °C, 2,270 °F) |
| Boiling point | 2,334 K (2,060 °C, 3,740 °F) |
| Density | 7.3 g/cm³ |
| Electronegativity (Pauling) | 1.55 |
| Atomic radius | 197 pm |
| First ionization energy | 7.434 eV |
| Electron affinity | — |
| Oxidation states | +7, +4, +3, +2 |
| Common ion charge | +7, +4 |
| Discovered | 1774 by Torbern Olof Bergman |
Where manganese sits on the periodic table
Group 7: Technetium, Rhenium, Bohrium.
Questions about manganese
How many valence electrons does manganese have?
Manganese has 2 valence electrons in its outer shell; inner d or f electrons can also bond.
How many protons, neutrons and electrons does manganese have?
A neutral manganese atom has 25 protons and 25 electrons. Its most common form has about 30 neutrons (mass number 55 − 25 protons).
What is the electron configuration of manganese?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵, written in short form as [Ar] 4s² 3d⁵.
What does the Bohr model of manganese look like?
A nucleus of 25 protons and 30 neutrons, circled by 4 electron shells holding 2, 8, 13, 2 electrons.
What is the atomic number of manganese?
25. The atomic number is the number of protons in the nucleus, and it is what makes an atom manganese.