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Promethium vs Fermium

Promethium
Fermium
Fermium vs Promethium


Periodic Table
Symbol
Pm  
Fm  
Group Number
3  
15
3  
15
Period Number
6  
7  
Block
f block  
f block  
Element Family
Lanthanide  
Actinide  
CAS Number
7440122  
99+
7440724  
19
Space Group Name
-  
-  
Space Group Number
194.00  
7
194.00  
7
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
  
  
Abundance In Universe
0.00 %  
40
0.00 %  
35
Abundance In Sun
-  
0.00 %  
30
Abundance In Meteorites
-  
0.00 %  
99+
Abundance In Earth's Crust
0.00 %  
99+
0.00 %  
99+
Abundance In Oceans
-  
-  
Abundance In Humans
0.00 %  
24
-  
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
-  
-  
Medical Uses
-  
-  
Other Uses
-  
-  
Biological Properties
  
  
Toxicity
Non Toxic  
-  
Present in Human Body
No  
No  
In Blood
0.00 Blood/mg dm-3  
40
0.00 Blood/mg dm-3  
40
In Bone
0.00 p.p.m.  
99+
0.00 p.p.m.  
99+
Physical
Melting Point
1,042.00 °C  
99+
1,527.00 °C  
26
Boiling Point
3,000.00 °C  
32
0.00 °C  
99+
Appearance
  
  
Physical State
Solid  
Solid  
Color
-  
-  
Luster
Metallic  
-  
Hardness
  
  
Mohs Hardness
-  
6.00  
6
Brinell Hardness
400.00 MPa  
34
500.00 MPa  
28
Vickers Hardness
600.00 MPa  
28
600.00 MPa  
28
Speed of Sound
2,260.00 m/s  
99+
2,500.00 m/s  
99+
Optical Properties
  
  
Refractive Index
1.70  
27
1.30  
99+
Reflectivity
63.00 %  
20
59.00 %  
24
Allotropes
No  
No  
α Allotropes
-  
-  
β Allotropes
-  
-  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Pm  
Fm  
Isotopes
  
  
Known Isotopes
27  
12
18  
21
Electronegativity
  
  
Pauling Electronegativity
1.13  
99+
1.30  
33
Sanderson Electronegativity
1.13  
36
1.30  
25
Allred Rochow Electronegativity
1.07  
33
1.20  
28
Mulliken-Jaffe Electronegativity
1.13  
99+
1.30  
33
Allen Electronegativity
1.13  
99+
1.30  
40
Electropositivity
  
  
Pauling Electropositivity
2.20  
39
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  
99+
3,792.00 kJ/mol  
99+
5th Energy Level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
39
6th Energy Level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
7th Energy level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
8th Energy Level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
9th Energy Level
5,400.00 kJ/mol  
99+
7,040.00 kJ/mol  
33
10th Energy Level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
11th Energy Level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
12th Energy Level
5,400.00 kJ/mol  
99+
62,700.00 kJ/mol  
10
13th Energy Level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
38
14th Energy Level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
27
15th Energy Level
54,000.00 kJ/mol  
99+
62,700.00 kJ/mol  
38
16th Energy Level
54,000.00 kJ/mol  
99+
62,700.00 kJ/mol  
28
17th Energy Level
540.50 kJ/mol  
99+
627.00 kJ/mol  
99+
18th Energy Level
5,400.00 kJ/mol  
99+
6,270.00 kJ/mol  
40
19th Energy Level
540.00 kJ/mol  
99+
994.80 kJ/mol  
21
20th Energy Level
540.00 kJ/mol  
99+
627.00 kJ/mol  
99+
21st Energy Level
540.00 kJ/mol  
99+
627.00 kJ/mol  
99+
22nd Energy Level
540.00 kJ/mol  
99+
345.00 kJ/mol  
99+
23rd Energy Level
540.00 kJ/mol  
99+
6,270.00 kJ/mol  
14
24th Energy Level
540.00 kJ/mol  
99+
627.60 kJ/mol  
38
25th Energy Level
540.00 kJ/mol  
99+
627.00 kJ/mol  
40
26th Energy Level
540.00 kJ/mol  
99+
627.60 kJ/mol  
39
27th Energy Level
540.00 kJ/mol  
99+
627.60 kJ/mol  
99+
28th Energy Level
540.00 kJ/mol  
99+
627.60 kJ/mol  
99+
29th Energy Level
540.00 kJ/mol  
99+
627.60 kJ/mol  
99+
30th Energy Level
540.00 kJ/mol  
99+
627.60 kJ/mol  
99+
Electrochemical Equivalent
1.80 g/amp-hr  
40
3.20 g/amp-hr  
15
Electron Work Function
5.30 eV  
5
4.47 eV  
21
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility  
Ionization, Radioactive Isotopes, Radioactivity  
Atomic
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  
99+
157  
8
Number of Electrons
61  
99+
100  
18
Radius of an Atom
  
  
Atomic Radius
183.00 pm  
12
180.00 pm  
16
Covalent Radius
199.00 pm  
12
180.00 pm  
23
Van der Waals Radius
236.00 pm  
20
245.00 pm  
13
Atomic Weight
145.00 amu  
99+
257.00 amu  
15
Atomic Volume
22.39 cm3/mol  
21
18.00 cm3/mol  
99+
Adjacent Atomic Numbers
  
  
Previous Element
Neodymium
  
Einsteinium
  
Next Element
Samarium
  
Mendelevium
  
Valence Electron Potential
44.10 (-eV)  
40
0.00 (-eV)  
99+
Lattice Constant
-  
350.00 pm  
99+
Lattice Angles
-  
-  
Lattice C/A Ratio
1.63  
14
1.63  
13
Mechanical
Density
  
  
Density At Room Temperature
7.26 g/cm3  
99+
9.70 g/cm3  
99+
Density When Liquid (at m.p.)
7.26 g/cm3  
99+
9.70 g/cm3  
99+
Tensile Strength
75.00 MPa  
30
0.10 MPa  
99+
Viscosity
0.00  
25
0.00  
25
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
37
0.00 (Pa)  
22
Vapor Pressure at 2000 K
0.00 (Pa)  
31
0.00 (Pa)  
30
Elasticity properties
  
  
Shear Modulus
18.00 GPa  
99+
30.00 GPa  
27
Bulk Modulus
33.00 GPa  
99+
50.00 GPa  
24
Young's Modulus
46.00 GPa  
99+
0.00 GPa  
99+
Poisson Ratio
0.28  
17
0.35  
9
Other Mechanical Properties
-  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
7.26  
99+
9.70  
99+
Magnetic Ordering
Paramagnetic  
-  
Permeability
0.00 H/m  
11
0.00 H/m  
16
Susceptibility
0.00  
25
0.00  
24
Electrical Properties
  
  
Electrical Property
Conductor  
-  
Resistivity
0.75 nΩ·m  
99+
7.90 nΩ·m  
99+
Electrical Conductivity
0.00 106/cm Ω  
99+
0.00 106/cm Ω  
99+
Electron Affinity
50.00 kJ/mol  
26
0.00 kJ/mol  
99+
Thermal
Specific Heat
0.18 J/(kg K)  
34
0.10 J/(kg K)  
99+
Molar Heat Capacity
27.60 J/mol·K  
20
27.00 J/mol·K  
29
Thermal Conductivity
17.90 W/m·K  
99+
0.00 W/m·K  
99+
Critical Temperature
1,315.00 K  
99+
1,323.00 K  
99+
Thermal Expansion
9.00 µm/(m·K)  
99+
11.00 µm/(m·K)  
99+
Enthalpy
  
  
Enthalpy of Vaporization
289.00 kJ/mol  
99+
319.20 kJ/mol  
99+
Enthalpy of Fusion
7.50 kJ/mol  
99+
13.30 kJ/mol  
30
Enthalpy of Atomization
310.00 kJ/mol  
99+
-  
Standard Molar Entropy
57.00 J/mol.K  
30
50.00 J/mol.K  
99+
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