Symbol
Co
  
Rb
  
Period Number
4
  
5
  
Block
d block
  
s block
  
Element Family
Transition Metal
  
Alkali
  
Space Group Name
P63/mmc
  
Im_ 3m
  
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.
  
- Rubidium metal is 16th most common element found in the earth crust.
- Rubidium metal also found in minerals as well as seawater.
  
Sources
Found in Compounds, Mining, Ores of Minerals
  
Obtained from Lithium Production.
  
History
  
  
Who Discovered
Georg Brandt
  
Robert Bunsen and Gustav Kirchhoff
  
Discovery
In 1732
  
In 1861
  
Abundance
  
  
Abundance In Sun
~0.000003 %
  
17
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.
  
- Rubidium's main application is in the glass manufacturing.
- Rubidium can very easily get ionized and hence it is used for ion engines, but it is still less efficient than that of Caesium.
  
Industrial Uses
Chemical Industry, Electrical Industry, Electronic Industry
  
NA
  
Medical Uses
Pharmaceutical Industry
  
NA
  
Other Uses
Alloys
  
Alloys, Research Purposes
  
Biological Properties
  
  
Toxicity
Toxic
  
Non Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
0.04 Blood/mg dm-3
  
18
2.49 Blood/mg dm-3
  
7
In Bone
0.04 p.p.m.
  
27
5.00 p.p.m.
  
13
Melting Point
1,495.00 °C
  
29
Boiling Point
2,870.00 °C
  
34
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Grayish White
  
Luster
Metallic
  
NA
  
Hardness
  
  
Vickers Hardness
1,043.00 MPa
  
11
Not Available
  
Speed of Sound
4,720.00 m/s
  
14
1,300.00 m/s
  
99+
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
Yes
  
No
  
α Allotropes
α-Cobalt
  
Not Available
  
β Allotropes
β-Cobalt
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Co
  
Rb
  
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
403.00 kJ/mol
  
99+
2nd Energy Level
1,648.00 kJ/mol
  
31
2,633.00 kJ/mol
  
6
3rd Energy Level
3,232.00 kJ/mol
  
22
3,860.00 kJ/mol
  
11
4th Energy Level
4,950.00 kJ/mol
  
19
5,080.00 kJ/mol
  
18
5th Energy Level
7,670.00 kJ/mol
  
12
6,850.00 kJ/mol
  
19
6th Energy Level
9,840.00 kJ/mol
  
12
8,140.00 kJ/mol
  
20
7th Energy level
12,440.00 kJ/mol
  
11
9,570.00 kJ/mol
  
20
8th Energy Level
15,230.00 kJ/mol
  
12
13,120.00 kJ/mol
  
17
9th Energy Level
17,959.00 kJ/mol
  
13
14,500.00 kJ/mol
  
18
10th Energy Level
26,570.00 kJ/mol
  
7
26,740.00 kJ/mol
  
6
11th Energy Level
29,400.00 kJ/mol
  
8
Not Available
  
12th Energy Level
32,400.00 kJ/mol
  
8
Not Available
  
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+
3.19 g/amp-hr
  
14
Other Chemical Properties
Chemical Stability, Ionization
  
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Ar] 3d2 4s2
  
[Kr] 5s1
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
HCP-Crystal-Structure-of-Cobalt.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
10.64 cm3/mol
  
99+
55.90 cm3/mol
  
2
Adjacent Atomic Numbers
  
  
Valence Electron Potential
95.20 (-eV)
  
10
9.47 (-eV)
  
99+
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
4.51 g/cm3
  
99+
1.53 g/cm3
  
99+
Density When Liquid (at m.p.)
4.11 g/cm3
  
99+
1.46 g/cm3
  
99+
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Poor Conductor
  
Conductor
  
Resistivity
420.00 nΩ·m
  
12
128.00 nΩ·m
  
26
Electrical Conductivity
0.02 106/cm Ω
  
99+
0.08 106/cm Ω
  
24
Electron Affinity
7.60 kJ/mol
  
37
46.90 kJ/mol
  
24
Specific Heat
0.52 J/(kg K)
  
9
0.36 J/(kg K)
  
17
Molar Heat Capacity
25.06 J/mol·K
  
99+
31.06 J/mol·K
  
5
Thermal Conductivity
21.90 W/m·K
  
99+
58.20 W/m·K
  
26
Critical Temperature
Not Available
  
Thermal Expansion
8.60 µm/(m·K)
  
99+
90.00 µm/(m·K)
  
2
Enthalpy
  
  
Enthalpy of Vaporization
429.00 kJ/mol
  
15
69.20 kJ/mol
  
99+
Enthalpy of Fusion
15.48 kJ/mol
  
19
2.19 kJ/mol
  
99+
Enthalpy of Atomization
468.60 kJ/mol
  
15
82.00 kJ/mol
  
99+
Standard Molar Entropy
27.30 J/mol.K
  
99+
76.80 J/mol.K
  
5