Symbol
Co
  
Mg
  
Period Number
4
  
3
  
Block
d block
  
s block
  
Element Family
Transition Metal
  
Alkaline Earth
  
Space Group Name
P63/mmc
  
P63/mmc
  
Interesting Facts
- The main source of Cobalt is as a by-product of copper and nickel metal mining.
- Cobalt metal can be obtained from other elements like Oxygen, Sulfur and Arsenic.
- It s also used in electroplating process as it exhibits anti cession properties.
  
- Magnesium ions are present in every chlorophyll of every green plant .
- Controlling Magnesium fire by pouring water on it will result in explosions.
  
Sources
Found in Compounds, Mining, Ores of Minerals
  
By Electrolysis Process, In Ocean, Mining
  
History
  
  
Who Discovered
Georg Brandt
  
Joseph Black
  
Discovery
In 1732
  
In 1755
  
Abundance
  
  
Abundance In Earth's Crust
Uses & Benefits
- Its alloys with aluminum and nickel are used to make powerful magnets.
-
Few other alloys exhibit high-temperature strength and hence they are used in Turbines of Jet and Gas engine.
  
- Magnesium aluminum alloy improves the mechanical strength and welding characteristics and hence it is used in aeroplane and car manufacturing.
-
It is also used to remove sulfur from the molten iron and steel.
  
Industrial Uses
Chemical Industry, Electrical Industry, Electronic Industry
  
Aerospace Industry, Ammunition Industry, Automobile Industry, Chemical Industry, Pharmaceutical Industry
  
Medical Uses
Pharmaceutical Industry
  
NA
  
Other Uses
Alloys
  
Surgical Instruments Manufacturing
  
Biological Properties
  
  
Toxicity
Toxic
  
Non Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
0.04 Blood/mg dm-3
  
18
37.80 Blood/mg dm-3
  
5
In Bone
0.04 p.p.m.
  
27
1,800.00 p.p.m.
  
4
Melting Point
1,495.00 °C
  
29
Boiling Point
2,870.00 °C
  
34
1,107.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Gray
  
Luster
Metallic
  
NA
  
Hardness
  
  
Vickers Hardness
1,043.00 MPa
  
11
Not Available
  
Speed of Sound
4,720.00 m/s
  
14
4,940.00 m/s
  
11
Optical Properties
  
  
Allotropes
Yes
  
No
  
α Allotropes
α-Cobalt
  
Not Available
  
β Allotropes
β-Cobalt
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Co
  
Mg
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
760.40 kJ/mol
  
19
737.70 kJ/mol
  
24
2nd Energy Level
1,648.00 kJ/mol
  
31
1,450.70 kJ/mol
  
99+
3rd Energy Level
3,232.00 kJ/mol
  
22
7,732.70 kJ/mol
  
5
4th Energy Level
4,950.00 kJ/mol
  
19
10,542.50 kJ/mol
  
4
5th Energy Level
7,670.00 kJ/mol
  
12
13,630.00 kJ/mol
  
3
6th Energy Level
9,840.00 kJ/mol
  
12
18,020.00 kJ/mol
  
3
7th Energy level
12,440.00 kJ/mol
  
11
21,711.00 kJ/mol
  
3
8th Energy Level
15,230.00 kJ/mol
  
12
25,661.00 kJ/mol
  
3
9th Energy Level
17,959.00 kJ/mol
  
13
31,653.00 kJ/mol
  
3
10th Energy Level
26,570.00 kJ/mol
  
7
35,458.00 kJ/mol
  
5
11th Energy Level
29,400.00 kJ/mol
  
8
169,988.00 kJ/mol
  
1
12th Energy Level
32,400.00 kJ/mol
  
8
189,368.00 kJ/mol
  
1
13th Energy Level
36,600.00 kJ/mol
  
8
Not Available
  
14th Energy Level
39,700.00 kJ/mol
  
9
Not Available
  
15th Energy Level
42,800.00 kJ/mol
  
12
Not Available
  
16th Energy Level
49,396.00 kJ/mol
  
11
Not Available
  
17th Energy Level
52,737.00 kJ/mol
  
13
Not Available
  
18th Energy Level
134,810.00 kJ/mol
  
1
Not Available
  
19th Energy Level
145,170.00 kJ/mol
  
2
Not Available
  
20th Energy Level
154,700.00 kJ/mol
  
4
Not Available
  
21st Energy Level
167,400.00 kJ/mol
  
4
Not Available
  
22nd Energy Level
178,100.00 kJ/mol
  
3
Not Available
  
23rd Energy Level
189,300.00 kJ/mol
  
3
Not Available
  
Electrochemical Equivalent
1.10 g/amp-hr
  
99+
0.45 g/amp-hr
  
99+
Other Chemical Properties
Chemical Stability, Ionization
  
Corrosion, Highly Inflammable, Ionization, Solubility
  
Electron Configuration
[Ar] 3d2 4s2
  
[Ne] 3s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Hexagonal Close Packed (HCP)
  
Crystal Lattice
HCP-Crystal-Structure-of-Cobalt.jpg#100
  
HCP-Crystal-Structure-of-Magnesium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
10.64 cm3/mol
  
99+
13.97 cm3/mol
  
37
Adjacent Atomic Numbers
  
  
Valence Electron Potential
95.20 (-eV)
  
10
40.00 (-eV)
  
99+
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, 2 π/3
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
4.51 g/cm3
  
99+
1.74 g/cm3
  
99+
Density When Liquid (at m.p.)
4.11 g/cm3
  
99+
1.58 g/cm3
  
99+
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Ductile
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Poor Conductor
  
Conductor
  
Resistivity
420.00 nΩ·m
  
12
43.90 nΩ·m
  
99+
Electrical Conductivity
0.02 106/cm Ω
  
99+
0.23 106/cm Ω
  
7
Electron Affinity
7.60 kJ/mol
  
37
0.00 kJ/mol
  
40
Specific Heat
0.52 J/(kg K)
  
9
1.02 J/(kg K)
  
4
Molar Heat Capacity
25.06 J/mol·K
  
99+
24.87 J/mol·K
  
99+
Thermal Conductivity
21.90 W/m·K
  
99+
156.00 W/m·K
  
8
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
8.60 µm/(m·K)
  
99+
24.80 µm/(m·K)
  
15
Enthalpy
  
  
Enthalpy of Vaporization
429.00 kJ/mol
  
15
128.70 kJ/mol
  
99+
Enthalpy of Fusion
15.48 kJ/mol
  
19
8.95 kJ/mol
  
39
Enthalpy of Atomization
468.60 kJ/mol
  
15
148.50 kJ/mol
  
99+
Standard Molar Entropy
27.30 J/mol.K
  
99+
32.70 J/mol.K
  
99+