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Samarium vs Protactinium


Protactinium vs Samarium


Periodic Table

Symbol
Sm   
Pa   

Group Number
Not Available   
Not Available   

Period Number
6   
7   

Block
f block   
f block   

Element Family
Lanthanide   
Actinide   

CAS Number
7440199   
99+
7440133   
99+

Space Group Name
R_ 3m   
I4/mmm   

Space Group Number
166.00   
6
139.00   
8

Facts

Interesting Facts
  • Samarium metals helps stimulating body metabolism.
  • Samarium metals was 1st observed by Jean Charles Galissard de Marignac in Dydimia in 1853.
  
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  

Sources
Found in Minerals, Mining, Ores of Minerals   
Found in Uranium Ores, Mining, Ores of metals   

History
  
  

Who Discovered
Lecoq de Boisbaudran   
William Crookes   

Discovery
In 1879   
In 1900   

Abundance
  
  

Abundance In Universe
5 * 10-7 %   
19
Not Available   

Abundance In Sun
~0.0000001 %   
26
~-9999 %   

Abundance In Meteorites
0.00 %   
37
Not Available   

Abundance In Earth's Crust
0.00 %   
29
0.00 %   
99+

Abundance In Oceans
0.00 %   
40
0.00 %   
99+

Uses

Uses & Benefits
  • 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.
  
  • Currently known uses of Protactinium metal are limited to research purpose only.
  

Industrial Uses
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys, In Nuclear Reactors   
NA   

Biological Properties
  
  

Toxicity
Slightly Toxic   
Highly Toxic   

Present in Human Body
Yes   
No   

In Blood
0.01 Blood/mg dm-3   
22
0.00 Blood/mg dm-3   
37

In Bone
Not Available   
0.00 p.p.m.   
36

Physical Properties

Melting Point
1,072.00 °C   
99+
1,568.00 °C   
21

Boiling Point
1,900.00 °C   
99+
4,027.00 °C   
12

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Silver   

Luster
Lustrous   
Metallic   

Hardness
  
  

Brinell Hardness
441.00 MPa   
27
Not Available   

Vickers Hardness
412.00 MPa   
24
Not Available   

Speed of Sound
2,130.00 m/s   
99+
Not Available   

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
Sm   
Pa   

Isotopes
  
  

Known Isotopes
30   
9
27   
12

Electronegativity
  
  

Pauling Electronegativity
1.17   
40
1.50   
27

Allred Rochow Electronegativity
1.07   
32
1.14   
28

Electropositivity
  
  

Pauling Electropositivity
2.83   
14
2.50   
27

Ionization Energies
  
  

1st Energy Level
544.50 kJ/mol   
99+
568.00 kJ/mol   
99+

2nd Energy Level
1,070.00 kJ/mol   
99+
1,128.00 kJ/mol   
99+

3rd Energy Level
2,260.00 kJ/mol   
99+
1,814.00 kJ/mol   
99+

4th Energy Level
3,990.00 kJ/mol   
37
2,991.00 kJ/mol   
99+

Electrochemical Equivalent
1.87 g/amp-hr   
34
1.72 g/amp-hr   
99+

Electron Work Function
2.70 eV   
99+
Not Available   

Other Chemical Properties
Ionization, Radioactive Isotopes   
Ionization, Radioactive Isotopes, Radioactivity   

Atomic Properties

Atomic Number
62   
99+
91   
27

Electron Configuration
[Xe] 4f6 6s2   
[Rn] 5f2 6d1 7s2   

Crystal Structure
Rhombohedral (RHO)   
Tetragonal (TETR)   

Crystal Lattice
RHO-Crystal-Structure-of-Samarium.jpg#100   
TETR-Crystal-Structure-of-Protactinium.jpg#100   

Atom
  
  

Number of Protons
62   
99+
91   
27

Number of Neutrons
88   
39
122   
21

Number of Electrons
62   
99+
91   
27

Radius of an Atom
  
  

Atomic Radius
180.00 pm   
14
163.00 pm   
25

Covalent Radius
198.00 pm   
13
200.00 pm   
11

Van der Waals Radius
229.00 pm   
20
243.00 pm   
11

Atomic Weight
150.36 amu   
99+
231.04 amu   
24

Atomic Volume
19.95 cm3/mol   
19
15.00 cm3/mol   
34

Adjacent Atomic Numbers
  
  

Previous Element
Promethium
  
Thorium
  

Next Element
Europium
  
Uranium
  

Valence Electron Potential
44.80 (-eV)   
37
92.00 (-eV)   
11

Lattice Constant
362.10 pm   
33
392.50 pm   
23

Lattice Angles
π/2, π/2, 2 π/3   
π/2, π/2, π/2   

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
7.52 g/cm3   
99+
15.37 g/cm3   
20

Density When Liquid (at m.p.)
7.16 g/cm3   
32
Not Available   

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.94 (Pa)   
9
Not Available   

Elasticity properties
  
  

Shear Modulus
19.50 GPa   
34
Not Available   

Bulk Modulus
37.80 GPa   
35
Not Available   

Young's Modulus
49.70 GPa   
37
Not Available   

Poisson Ratio
0.27   
19
Not Available   

Other Mechanical Properties
NA   
Unknown   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
7.52   
99+
15.37   
12

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
0.94 nΩ·m   
99+
177.00 nΩ·m   
21

Electrical Conductivity
0.01 106/cm Ω   
99+
0.05 106/cm Ω   
34

Electron Affinity
50.00 kJ/mol   
21
Not Available   

Thermal Properties

Specific Heat
0.20 J/(kg K)   
31
0.12 J/(kg K)   
40

Molar Heat Capacity
29.54 J/mol·K   
7
Not Available   

Thermal Conductivity
13.30 W/m·K   
99+
47.00 W/m·K   
32

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
12.70 µm/(m·K)   
30
9.90 µm/(m·K)   
40

Enthalpy
  
  

Enthalpy of Vaporization
166.40 kJ/mol   
99+
Not Available   

Enthalpy of Fusion
8.62 kJ/mol   
40
12.34 kJ/mol   
28

Enthalpy of Atomization
209.00 kJ/mol   
99+
Not Available   

Standard Molar Entropy
69.60 J/mol.K   
15
198.10 J/mol.K   
1

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