Strontium vs Cadmium
Periodic Table
Symbol
Sr
Cd
Group Number
2
16
12
6
Period Number
5
5
Block
s block
d block
Element Family
Alkaline Earth
Transition Metal
CAS Number
7440246
99+
7440439
99+
Space Group Name
Fm_ 3m
P63/mmc
Space Group Number
225.00
2
194.00
5
Facts
Interesting Facts
- Strontium element is softer than Calcium.
- Silvery Strontium turns yellow, if exposed to air.
- Naturally occurring minor elements include Cadmium.
- Cadmium is released into atmosphere to control volcanic eruption and forest fires.
- It is used for electroplating of Steel for corrosion resistance.
- It can absorb neutrons and used in nuclear reactor to control atomic fission.
Sources
Found in Minerals, Mining, Ores of Minerals
Found As a By-product, Found in Minerals, Mining
History
Who Discovered
William Cruickshank
Karl Samuel Leberecht Hermann and Friedrich Stromeyer
Discovery
In 1787
In 1817
Abundance
Abundance In Universe
4 * 10-6 %
14
2 * 10-7 %
22
Abundance In Sun
~0.000005 %
15
~0.0000006 %
21
Abundance In Meteorites
0.00 %
15
0.00 %
31
Abundance In Earth's Crust
0.04 %
10
0.00 %
99+
Abundance In Oceans
0.00 %
4
0.00 %
28
Abundance In Humans
0.00 %
7
0.00 %
11
Uses
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.
- It has very limited uses as it is a toxic metal and it can cause birth defects, cancer, etc.
- Almost 80% of Cadmium metal is used in Nickel cadmium Batteries and now it is getting replaced with nickel hydride.
Industrial Uses
Ammunition Industry, Chemical Industry
Aerospace Industry, Ammunition Industry, Chemical Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
NA
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
0.01 Blood/mg dm-3
24
In Bone
140.00 p.p.m.
7
1.80 p.p.m.
15
Physical Properties
Melting Point
769.00 °C
99+
320.90 °C
99+
Boiling Point
1,384.00 °C
99+
765.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery Bluish-Gray
Luster
Metallic
Metallic
Hardness
Mohs Hardness
1.50
18
2.00
16
Brinell Hardness
Not Available
203.00 MPa
39
Speed of Sound
Not Available
2,310.00 m/s
39
Optical Properties
Reflectivity
Not Available
67.00 %
11
Allotropes
No
No
α Allotropes
Not Available
Not Available
β Allotropes
Not Available
Not Available
γ Allotropes
Not Available
Not Available
Chemical Properties
Chemical Formula
Sr
Cd
Isotopes
Known Isotopes
27
12
34
5
Electronegativity
Pauling Electronegativity
0.95
99+
1.69
17
Sanderson Electronegativity
0.72
27
1.98
9
Allred Rochow Electronegativity
0.99
37
1.46
15
Mulliken-Jaffe Electronegativity
1.00
18
1.53
13
Allen Electronegativity
0.96
40
1.52
27
Electropositivity
Pauling Electropositivity
3.05
7
2.31
37
Ionization Energies
1st Energy Level
549.50 kJ/mol
99+
867.80 kJ/mol
11
2nd Energy Level
1,064.20 kJ/mol
99+
1,631.40 kJ/mol
32
3rd Energy Level
4,138.00 kJ/mol
10
3,616.00 kJ/mol
13
4th Energy Level
5,500.00 kJ/mol
13
Not Available
5th Energy Level
6,910.00 kJ/mol
18
Not Available
6th Energy Level
8,760.00 kJ/mol
18
Not Available
7th Energy level
10,230.00 kJ/mol
19
Not Available
8th Energy Level
11,800.00 kJ/mol
19
Not Available
9th Energy Level
15,600.00 kJ/mol
17
Not Available
10th Energy Level
17,100.00 kJ/mol
19
Not Available
11th Energy Level
31,270.00 kJ/mol
6
Not Available
Electrochemical Equivalent
1.64 g/amp-hr
99+
2.10 g/amp-hr
27
Electron Work Function
2.59 eV
99+
4.22 eV
22
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
38
99+
48
99+
Electron Configuration
[Kr] 5s2
[Kr] 4d10 5s2
Crystal Structure
Face Centered Cubic (FCC)
Hexagonal Close Packed (HCP)
Crystal Lattice
FCC-Crystal-Structure-of-Strontium.jpg#100
HCP-Crystal-Structure-of-Cadmium.jpg#100
Atom
Number of Protons
38
99+
48
99+
Number of Neutrons
50
99+
64
99+
Number of Electrons
38
99+
48
99+
Radius of an Atom
Atomic Radius
215.00 pm
5
151.00 pm
32
Covalent Radius
195.00 pm
15
144.00 pm
40
Van der Waals Radius
249.00 pm
7
158.00 pm
99+
Atomic Weight
87.62 amu
99+
112.41 amu
99+
Atomic Volume
33.70 cm3/mol
6
13.10 cm3/mol
39
Adjacent Atomic Numbers
Valence Electron Potential
25.70 (-eV)
99+
30.00 (-eV)
99+
Lattice Constant
608.49 pm
6
297.94 pm
99+
Lattice Angles
π/2, π/2, π/2
π/2, π/2, 2 π/3
Lattice C/A Ratio
Not Available
1.89
1
Mechanical Properties
Density
Density At Room Temperature
2.64 g/cm3
99+
8.65 g/cm3
99+
Density When Liquid (at m.p.)
2.38 g/cm3
99+
8.00 g/cm3
28
Tensile Strength
Not Available
62.00 MPa
16
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
121.00 (Pa)
1
Not Available
Elasticity properties
Shear Modulus
6.03 GPa
99+
19.00 GPa
35
Bulk Modulus
Not Available
42.00 GPa
29
Young's Modulus
15.70 GPa
99+
50.00 GPa
36
Poisson Ratio
0.28
17
0.30
14
Other Mechanical Properties
NA
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
2.64
99+
8.65
36
Magnetic Ordering
Paramagnetic
Diamagnetic
Electrical Properties
Electrical Property
NA
Semiconductor
Resistivity
132.00 nΩ·m
24
72.70 nΩ·m
36
Electrical Conductivity
0.08 106/cm Ω
26
0.14 106/cm Ω
15
Electron Affinity
5.03 kJ/mol
38
0.00 kJ/mol
40
Thermal Properties
Specific Heat
0.30 J/(kg K)
18
0.23 J/(kg K)
26
Molar Heat Capacity
26.40 J/mol·K
28
26.02 J/mol·K
32
Thermal Conductivity
35.40 W/m·K
37
96.60 W/m·K
16
Critical Temperature
Not Available
Not Available
Thermal Expansion
22.50 µm/(m·K)
18
30.80 µm/(m·K)
10
Enthalpy
Enthalpy of Vaporization
150.00 kJ/mol
99+
100.00 kJ/mol
99+
Enthalpy of Fusion
9.16 kJ/mol
38
6.19 kJ/mol
99+
Enthalpy of Atomization
163.20 kJ/mol
99+
113.00 kJ/mol
99+
Standard Molar Entropy
55.00 J/mol.K
26
51.80 J/mol.K
27
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