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Element 25 - Manganese (Mn)
From
magnes
, or magnet--its ore was first confused with magnetic iron ore; discovered 1774. Manganese, which gives steel a hard yet pliant quality, seems to play a similar role in animal bone: without it, bones grow spngier and break more easily. It activates many enzymes.
Properties
Atomic Number
:
25
Atomic Weight
:
54.9380
Electron Configuration
(at ground state):
1s
2
2s
2
2p
6
3s
2
3p
6
3d
5
4s
2
Oxidation States
(Bold most stable):
+2
, +3,
+4
, +6, +7
Boiling Point
(K):
2235
Melting Point (K):
1518
Density
(at 300K -- g/cm
3
):
7.44
Atomic Volume (at 300K -- cm
3
/mol)
7.39
Number of stable
isotopes
:
1
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
53 -- 2 x 10
6
years -- orbital
electron capture
54 -- 313.0 days -- orbital
electron capture
56 -- 2.578 hours --
beta particle
(
electron
) emission
Covalent Radius (Å):
1.17
Atomic Radius (Å):
1.35
First
Ionization Potential
(V):
7.435
Electronegativity
(Pauling's):
1.55
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.48
Heat of Vaporization (kJ/mol):
219.74
Heat of Fusion (kJ/mol):
14.64
Electrical Conductivity (at 293K for polycrystalline material -- 10
6
-1
cm
-1
):
0.5
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
7.82
Crystal Structure:
Cubic, body centered
Acid
-
Base
Properties:
Very acidic