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Promethium Fermium Comparison


Fermium Promethium comparison


Periodic Table

Symbol
Pm   
Fm   

Group Number
Not Available   
Not Available   

Period Number
6   
7   

Block
f block   
f block   

Element Family
Lanthanide   
Actinide   

CAS Number
7440122   
99+
7440724   
19

Space Group Name
Not Available   
Not Available   

Space Group Number
Not Available   
Not Available   

Facts

Interesting Facts
  • Promethium metal found in Pitchblende.
  • Promethium metal is highly radioactive metal.
  
  • Fermium metal is highly radioactive in nature.
  • Fermium is synthetically produced metal.
  

Sources
Found in Minerals, Mining   
Bombarding Pu-239 with Neutrons   

History
  
  

Who Discovered
Chien Shiung Wu, Emilio Segrè, Hans Bethe   
Lawrence Berkeley National Laboratory   

Discovery
In 1942   
In 1952   

Abundance
  
  

Uses

Uses & Benefits
  • It is used for research purpose. Very small amount of this metal is used in atomic batteries.
  • Its radioactive decay is used for a phosphor to give off light. The light emitted is converted into electricity.
  
  • Currently known uses of Fermium metal are limited to research purpose only.
  

Industrial Uses
NA   
NA   

Medical Uses
NA   
NA   

Other Uses
NA   
NA   

Biological Properties
  
  

Toxicity
Non Toxic   
Unknown   

Present in Human Body
No   
No   

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

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

Physical Properties

Melting Point
1,042.00 °C   
99+
1,527.00 °C   
26

Boiling Point
3,000.00 °C   
31
Not Available   

Appearance
  
  

Physical State
Solid   
Solid   

Luster
Metallic   
Not Defined   

Hardness
  
  

Speed of Sound
Not Available   
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
Pm   
Fm   

Isotopes
  
  

Known Isotopes
27   
12
18   
21

Electronegativity
  
  

Pauling Electronegativity
Not Available   
1.30   
32

Allred Rochow Electronegativity
1.07   
32
1.20   
27

Electropositivity
  
  

Pauling Electropositivity
Not Available   
2.70   
22

Ionization Energies
  
  

1st Energy Level
540.00 kJ/mol   
99+
627.00 kJ/mol   
99+

2nd Energy Level
1,050.00 kJ/mol   
99+
1,225.00 kJ/mol   
99+

3rd Energy Level
2,150.00 kJ/mol   
99+
2,363.00 kJ/mol   
99+

4th Energy Level
3,970.00 kJ/mol   
38
3,792.00 kJ/mol   
99+

Electrochemical Equivalent
1.80 g/amp-hr   
36
3.20 g/amp-hr   
13

Electron Work Function
Not Available   
Not Available   

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

Atomic Properties

Atomic Number
61   
99+
100   
18

Electron Configuration
[Xe] 4f5 6s2   
[Rn] 5f12 7s2   

Crystal Structure
Double Hexagonal Close Packed (DHCP)   
Not Known   

Crystal Lattice
DHCP-Crystal-Structure-of-Promethium.jpg#100   
Unknown-Crystal-Structure-of-Fermium.jpg#100   

Atom
  
  

Number of Protons
61   
99+
100   
18

Number of Neutrons
84   
40
157   
7

Number of Electrons
61   
99+
100   
18

Radius of an Atom
  
  

Atomic Radius
183.00 pm   
10
Not Available   

Covalent Radius
199.00 pm   
12
Not Available   

Van der Waals Radius
236.00 pm   
16
245.00 pm   
9

Atomic Weight
145.00 amu   
99+
257.00 amu   
15

Atomic Volume
22.39 cm3/mol   
12
Not Available   

Adjacent Atomic Numbers
  
  

Previous Element
Neodymium
  

Next Element
Samarium
  

Valence Electron Potential
44.10 (-eV)   
39
Not Available   

Lattice Constant
Not Available   
Not Available   

Lattice Angles
Unknown   
NA   

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
7.26 g/cm3   
99+
Not Available   

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Elasticity properties
  
  

Shear Modulus
18.00 GPa   
36
Not Available   

Bulk Modulus
33.00 GPa   
36
Not Available   

Young's Modulus
46.00 GPa   
38
Not Available   

Poisson Ratio
0.28   
17
Not Available   

Other Mechanical Properties
NA   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
7.26   
99+
Not Available   

Magnetic Ordering
Paramagnetic   
Unknown   

Electrical Properties
  
  

Electrical Property
Conductor   
Unknown   

Resistivity
0.75 nΩ·m   
99+
Not Available   

Electron Affinity
50.00 kJ/mol   
21
Not Available   

Thermal Properties

Specific Heat
0.18 J/(kg K)   
33
Not Available   

Molar Heat Capacity
Not Available   
Not Available   

Thermal Conductivity
17.90 W/m·K   
99+
Not Available   

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
9.00 µm/(m·K)   
99+
Not Available   

Enthalpy
  
  

Enthalpy of Fusion
7.50 kJ/mol   
99+
Not Available   

Enthalpy of Atomization
310.00 kJ/mol   
34
Not Available   

Standard Molar Entropy
Not Available   
Not Available   

Summary >>
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