• Class: Transition Metals
• Period: 4
• IUPAC group: 7
• Traditional: VIIa

• Discovered in: 1774 by Gahn
• Origin of name: Latin: magnes, (magnet)
• Historical or alternate name:

Pyrolusite & rhodochrosite as well as nodules on the ocean floor

Silvery, hard, brittle metal. Impure forms are reactive. Exposed surfaces oxidize.

• Atmosphere: ~0.0 ppm
• Primitive mantle: 1000.0 ppm
• Sea water: 0.002 ppm
• Metallic meteorite: 1960.0 ppm
• Continental crust: 1400.0 ppm
• Solar photosphere: 5.42 log of abundance
• Oceanic crust: 1000.0 ppm
• Solar system: 9510.0 relative to Si=1.0e6

   Hazards

Toxic. Flammable. Carcinogen. Compounds toxic by inhalation. Chronic poison..

• Lower:1.0
• Upper:100.0

Manganese Physical Properties

 Transitional Data

• State: Solid
• Density: 7.2 g/cm3

 Molar enthalpy

• Atomization: 279.37 kJ mol-1
• Fusion: 14.4 kJ mol-1
• Vaporization: 220.5 kJ mol-1

 Transition points

• Melting point: 1517.0 K
• Boiling point: 2235.0 K
• Critical temperature: 4327.0 K

 Molar properties

• Atomic weight: 54.93805 g/mole
• Molar volume: 7.42 cm3 mol-1

 Crystal structure sequence

complex-cubic <1368 K < face-centered-cubic < 1408 K < body-centered-cubic < melting point

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 32.01
  • Heat Capacity 26.32

• State: gas
  • Enthalpy 280.7
  • Gibbs function 238.5
  • Entropy 173.70
  • Heat Capacity 20.79

 Miscellaneous physical

• Electrical resistivity: 144.0 µ-ohms/cm
• Debye temperature: 410.0 K
• Thermal conductivity: 7.82 W / m / K
• Coefficient of linear expansion: 21.9Coef. per K
• Mass magnetic susceptibility: 1.21e-7
• X-ray diffraction mass absorption coefficients:
• CuK: 285 (µ/p)/cm2 g-1
• MoK: 34.7 (µ/p)/cm2 g-1

Manganese Chemical Properties

 Chemical basics:

• Oxidation states: +2 +3 +4 +6 +7
• Molecular wt: 54.93805 g/mole

 Radii

• Covalent: 117 pm
• Atomic: 137.0 pm
• Van der Waals: pm

 Ions:

• ion: +2 pm 83.0
• ion: +3 pm 64.5
• ion: +4 pm 53.0
• ion: +7 pm 46.0

 Covalent bonds

 Effective nuclear charge

• Slater: 3.60
• Clementi: 5.23
• Froese-Fischer: 7.17

 Electronegativity

• Pauling: 1.5
• Allred-Rochow: 1.60

 Standard reactions

Manganese Nuclear Properties

• Known 11
• Listed 3

• Known 50 - 58
• Listed 53 - 55

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 7/2
• Radioisotopes:
  • Half-life: 3.7 E6 years
  • Decay mode: E.C.,
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 312.0 days
  • Decay mode: E.C.,
  • Source:
• Notes med

• % Occ.:Natural 100.0%
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 5/2
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• Isotope Cross-section 13.3±0.1 barns

• Absolute sensitivity: 0.18 1H=1.0
• Relative sensitivity: 0.18 1H=1.0
• Receptivity: 994 13C=1.0
• Magnetogyric ratio: 6.6195e7 rad / T / s
• Quadropole moment: 0.55e-28 m2
• Frequency: 24.664 MHz
• Reference: KMnO4

Manganese Energy Properties

Electrons

• Ground state electron configuration: [Ar] 3d5 4s2
• Electron affinity: -94 kJ mol-1
• Filling orbitals:

Spectral lines

 Ionization energies

 Atomic energy levels