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Protactinium vs Samarium

Protactinium
Samarium
Samarium vs Protactinium


Periodic Table
Symbol
Pa   
Sm   
Group Number
Not Available   
Not Available   
Period Number
7   
6   
Block
f block   
f block   
Element Family
Actinide   
Lanthanide   
CAS Number
7440133   
99+
7440199   
99+
Space Group Name
I4/mmm   
R_ 3m   
Space Group Number
139.00   
8
166.00   
6
Facts
Interesting Facts
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  
  • Samarium metals helps stimulating body metabolism.
  • Samarium metals was 1st observed by Jean Charles Galissard de Marignac in Dydimia in 1853.
  
Sources
Found in Uranium Ores, Mining, Ores of metals   
Found in Minerals, Mining, Ores of Minerals   
History
  
  
Who Discovered
William Crookes   
Lecoq de Boisbaudran   
Discovery
In 1900   
In 1879   
Abundance
  
  
Abundance In Universe
Not Available   
5 * 10-7 %   
19
Abundance In Sun
~-9999 %   
~0.0000001 %   
26
Abundance In Meteorites
Not Available   
0.00 %   
37
Abundance In Earth's Crust
0.00 %   
99+
0.00 %   
29
Abundance In Oceans
0.00 %   
99+
0.00 %   
40
Uses
Uses & Benefits
  • Currently known uses of Protactinium metal are limited to research purpose only.
  
  • Magnets of Samarium cobalt alloy are stronger than that of Iron and hence, they are used in microwave application.
  • Samarium metal also used in optical lasers and infrared absorbing glasses and as a neutron absorber.
  
Industrial Uses
NA   
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry   
Medical Uses
NA   
NA   
Other Uses
NA   
Alloys, In Nuclear Reactors   
Biological Properties
  
  
Toxicity
Highly Toxic   
Slightly Toxic   
Present in Human Body
No   
Yes   
In Blood
0.00 Blood/mg dm-3   
37
0.01 Blood/mg dm-3   
22
In Bone
0.00 p.p.m.   
36
Not Available   
Physical Properties
Melting Point
1,568.00 °C   
21
1,072.00 °C   
99+
Boiling Point
4,027.00 °C   
12
1,900.00 °C   
99+
Appearance
  
  
Physical State
Solid   
Solid   
Color
Silver   
Silvery White   
Luster
Metallic   
Lustrous   
Hardness
  
  
Brinell Hardness
Not Available   
441.00 MPa   
27
Vickers Hardness
Not Available   
412.00 MPa   
24
Speed of Sound
Not Available   
2,130.00 m/s   
99+
Optical Properties
  
  
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
Pa   
Sm   
Isotopes
  
  
Known Isotopes
27   
12
30   
9
Electronegativity
  
  
Pauling Electronegativity
1.50   
27
1.17   
40
Allred Rochow Electronegativity
1.14   
28
1.07   
32
Electropositivity
  
  
Pauling Electropositivity
2.50   
27
2.83   
14
Ionization Energies
  
  
1st Energy Level
568.00 kJ/mol   
99+
544.50 kJ/mol   
99+
2nd Energy Level
1,128.00 kJ/mol   
99+
1,070.00 kJ/mol   
99+
3rd Energy Level
1,814.00 kJ/mol   
99+
2,260.00 kJ/mol   
99+
4th Energy Level
2,991.00 kJ/mol   
99+
3,990.00 kJ/mol   
37
Electrochemical Equivalent
1.72 g/amp-hr   
99+
1.87 g/amp-hr   
34
Electron Work Function
Not Available   
2.70 eV   
99+
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity   
Ionization, Radioactive Isotopes   
Atomic Properties
Atomic Number
91   
27
62   
99+
Electron Configuration
[Rn] 5f2 6d1 7s2   
[Xe] 4f6 6s2   
Crystal Structure
Tetragonal (TETR)   
Rhombohedral (RHO)   
Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100   
RHO-Crystal-Structure-of-Samarium.jpg#100   
Atom
  
  
Number of Protons
91   
27
62   
99+
Number of Neutrons
122   
21
88   
39
Number of Electrons
91   
27
62   
99+
Radius of an Atom
  
  
Atomic Radius
163.00 pm   
25
180.00 pm   
14
Covalent Radius
200.00 pm   
11
198.00 pm   
13
Van der Waals Radius
243.00 pm   
11
229.00 pm   
20
Atomic Weight
231.04 amu   
24
150.36 amu   
99+
Atomic Volume
15.00 cm3/mol   
34
19.95 cm3/mol   
19
Adjacent Atomic Numbers
  
  
Previous Element
Thorium
  
Promethium
  
Next Element
Uranium
  
Europium
  
Valence Electron Potential
92.00 (-eV)   
11
44.80 (-eV)   
37
Lattice Constant
392.50 pm   
23
362.10 pm   
33
Lattice Angles
π/2, π/2, π/2   
π/2, π/2, 2 π/3   
Lattice C/A Ratio
Not Available   
Not Available   
Mechanical Properties
Density
  
  
Density At Room Temperature
15.37 g/cm3   
20
7.52 g/cm3   
99+
Density When Liquid (at m.p.)
Not Available   
7.16 g/cm3   
32
Tensile Strength
Not Available   
Not Available   
Viscosity
Not Available   
Not Available   
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available   
0.94 (Pa)   
9
Elasticity properties
  
  
Shear Modulus
Not Available   
19.50 GPa   
34
Bulk Modulus
Not Available   
37.80 GPa   
35
Young's Modulus
Not Available   
49.70 GPa   
37
Poisson Ratio
Not Available   
0.27   
19
Other Mechanical Properties
Unknown   
NA   
Magnetic Properties
Magnetic Characteristics
  
  
Specific Gravity
15.37   
12
7.52   
99+
Magnetic Ordering
Paramagnetic   
Paramagnetic   
Electrical Properties
  
  
Electrical Property
Conductor   
Conductor   
Resistivity
177.00 nΩ·m   
21
0.94 nΩ·m   
99+
Electrical Conductivity
0.05 106/cm Ω   
34
0.01 106/cm Ω   
99+
Electron Affinity
Not Available   
50.00 kJ/mol   
21
Thermal Properties
Specific Heat
0.12 J/(kg K)   
40
0.20 J/(kg K)   
31
Molar Heat Capacity
Not Available   
29.54 J/mol·K   
7
Thermal Conductivity
47.00 W/m·K   
32
13.30 W/m·K   
99+
Critical Temperature
Not Available   
Not Available   
Thermal Expansion
9.90 µm/(m·K)   
40
12.70 µm/(m·K)   
30
Enthalpy
  
  
Enthalpy of Vaporization
Not Available   
166.40 kJ/mol   
99+
Enthalpy of Fusion
12.34 kJ/mol   
28
8.62 kJ/mol   
40
Enthalpy of Atomization
Not Available   
209.00 kJ/mol   
99+
Standard Molar Entropy
198.10 J/mol.K   
1
69.60 J/mol.K   
15
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