Symbol
Sr
  
Co
  
Period Number
5
  
4
  
Block
s block
  
d block
  
Element Family
Alkaline Earth
  
Transition Metal
  
Space Group Name
Fm_ 3m
  
P63/mmc
  
Interesting Facts
- Strontium element is softer than Calcium.
- Silvery Strontium turns yellow, if exposed to air.
  
- 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.
  
Sources
Found in Minerals, Mining, Ores of Minerals
  
Found in Compounds, Mining, Ores of Minerals
  
History
  
  
Who Discovered
William Cruickshank
  
Georg Brandt
  
Discovery
In 1787
  
In 1732
  
Abundance
  
  
Abundance In Sun
~0.000005 %
  
15
Abundance In Earth's Crust
Uses & Benefits
- Strontium metal is used to producing ferrite magnets as well as refining zinc.
-
By-product of nuclear reactors called Strontium-90 is a radioactive isotope; it is absorbed by tissues and destroys bone marrow and cancer growth.
  
- 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.
  
Industrial Uses
Ammunition Industry, Chemical Industry
  
Chemical Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
Pharmaceutical Industry
  
Other Uses
Alloys
  
Alloys
  
Biological Properties
  
  
Toxicity
Non Toxic
  
Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
0.03 Blood/mg dm-3
  
19
0.04 Blood/mg dm-3
  
18
In Bone
140.00 p.p.m.
  
7
0.04 p.p.m.
  
27
Melting Point
1,495.00 °C
  
29
Boiling Point
1,384.00 °C
  
99+
2,870.00 °C
  
34
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Gray
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Brinell Hardness
Not Available
  
Vickers Hardness
Not Available
  
1,043.00 MPa
  
11
Speed of Sound
Not Available
  
4,720.00 m/s
  
14
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
No
  
Yes
  
α Allotropes
Not Available
  
α-Cobalt
  
β Allotropes
Not Available
  
β-Cobalt
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Sr
  
Co
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
549.50 kJ/mol
  
99+
760.40 kJ/mol
  
19
2nd Energy Level
1,064.20 kJ/mol
  
99+
1,648.00 kJ/mol
  
31
3rd Energy Level
4,138.00 kJ/mol
  
10
3,232.00 kJ/mol
  
22
4th Energy Level
5,500.00 kJ/mol
  
13
4,950.00 kJ/mol
  
19
5th Energy Level
6,910.00 kJ/mol
  
18
7,670.00 kJ/mol
  
12
6th Energy Level
8,760.00 kJ/mol
  
18
9,840.00 kJ/mol
  
12
7th Energy level
10,230.00 kJ/mol
  
19
12,440.00 kJ/mol
  
11
8th Energy Level
11,800.00 kJ/mol
  
19
15,230.00 kJ/mol
  
12
9th Energy Level
15,600.00 kJ/mol
  
17
17,959.00 kJ/mol
  
13
10th Energy Level
17,100.00 kJ/mol
  
19
26,570.00 kJ/mol
  
7
11th Energy Level
31,270.00 kJ/mol
  
6
29,400.00 kJ/mol
  
8
12th Energy Level
Not Available
  
32,400.00 kJ/mol
  
8
13th Energy Level
Not Available
  
36,600.00 kJ/mol
  
8
14th Energy Level
Not Available
  
39,700.00 kJ/mol
  
9
15th Energy Level
Not Available
  
42,800.00 kJ/mol
  
12
16th Energy Level
Not Available
  
49,396.00 kJ/mol
  
11
17th Energy Level
Not Available
  
52,737.00 kJ/mol
  
13
18th Energy Level
Not Available
  
134,810.00 kJ/mol
  
1
19th Energy Level
Not Available
  
145,170.00 kJ/mol
  
2
20th Energy Level
Not Available
  
154,700.00 kJ/mol
  
4
21st Energy Level
Not Available
  
167,400.00 kJ/mol
  
4
22nd Energy Level
Not Available
  
178,100.00 kJ/mol
  
3
23rd Energy Level
Not Available
  
189,300.00 kJ/mol
  
3
Electrochemical Equivalent
1.64 g/amp-hr
  
99+
1.10 g/amp-hr
  
99+
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
  
Chemical Stability, Ionization
  
Electron Configuration
[Kr] 5s2
  
[Ar] 3d2 4s2
  
Crystal Structure
Face Centered Cubic (FCC)
  
Hexagonal Close Packed (HCP)
  
Crystal Lattice
FCC-Crystal-Structure-of-Strontium.jpg#100
  
HCP-Crystal-Structure-of-Cobalt.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
33.70 cm3/mol
  
6
10.64 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
25.70 (-eV)
  
99+
95.20 (-eV)
  
10
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, 2 π/3
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
2.64 g/cm3
  
99+
4.51 g/cm3
  
99+
Density When Liquid (at m.p.)
2.38 g/cm3
  
99+
4.11 g/cm3
  
99+
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Bulk Modulus
Not Available
  
Other Mechanical Properties
NA
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
NA
  
Poor Conductor
  
Resistivity
132.00 nΩ·m
  
24
420.00 nΩ·m
  
12
Electrical Conductivity
0.08 106/cm Ω
  
26
0.02 106/cm Ω
  
99+
Electron Affinity
5.03 kJ/mol
  
38
7.60 kJ/mol
  
37
Specific Heat
0.30 J/(kg K)
  
18
0.52 J/(kg K)
  
9
Molar Heat Capacity
26.40 J/mol·K
  
28
25.06 J/mol·K
  
99+
Thermal Conductivity
35.40 W/m·K
  
37
21.90 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
22.50 µm/(m·K)
  
18
8.60 µm/(m·K)
  
99+
Enthalpy
  
  
Enthalpy of Vaporization
150.00 kJ/mol
  
99+
429.00 kJ/mol
  
15
Enthalpy of Fusion
9.16 kJ/mol
  
38
15.48 kJ/mol
  
19
Enthalpy of Atomization
163.20 kJ/mol
  
99+
468.60 kJ/mol
  
15
Standard Molar Entropy
55.00 J/mol.K
  
26
27.30 J/mol.K
  
99+