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Erbium vs Fermium


Fermium vs Erbium


Periodic Table

Symbol
Er   
Fm   

Group Number
Not Available   
Not Available   

Period Number
6   
7   

Block
f block   
f block   

Element Family
Lanthanide   
Actinide   

CAS Number
7440520   
35
7440724   
19

Space Group Name
P63/mmc   
Not Available   

Space Group Number
194.00   
5
Not Available   

Facts

Interesting Facts
  • Erbium metal is used as alloyed with Vanadium to make it softer.
  • Recent studies shows that it is helpful for metabolism.
  
  • Fermium metal is highly radioactive in nature.
  • Fermium is synthetically produced metal.
  

Sources
Mining   
Bombarding Pu-239 with Neutrons   

History
  
  

Who Discovered
Carl Gustaf Mosander   
Lawrence Berkeley National Laboratory   

Discovery
In 1842   
In 1952   

Abundance
  
  

Abundance In Universe
2 * 10-7 %   
22
Not Available   

Abundance In Sun
~0.0000001 %   
26
~-9999 %   

Abundance In Meteorites
0.00 %   
36
Not Available   

Abundance In Earth's Crust
0.00 %   
32
Not Available   

Abundance In Oceans
0.00 %   
36
Not Available   

Uses

Uses & Benefits
  • It has a tendency to get tarnished in the open air, but when alloyed with elements like erbium, vanadium, its hardness levels decreases.
  • Its compounds like Erbium oxide is used in safety glasses of welders and metal workers.
  
  • Currently known uses of Fermium metal are limited to research purpose only.
  

Industrial Uses
Chemical Industry   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys   
NA   

Biological Properties
  
  

Toxicity
Mildly Toxic   
Unknown   

Present in Human Body
No   
No   

In Blood
Not Available   
0.00 Blood/mg dm-3   
37

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

Physical Properties

Melting Point
1,522.00 °C   
28
1,527.00 °C   
26

Boiling Point
2,510.00 °C   
99+
Not Available   

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Unknown   

Luster
Lustrous   
Not Defined   

Hardness
  
  

Brinell Hardness
814.00 MPa   
11
Not Available   

Vickers Hardness
589.00 MPa   
19
Not Available   

Speed of Sound
2,830.00 m/s   
28
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
Er   
Fm   

Isotopes
  
  

Known Isotopes
31   
8
18   
21

Electronegativity
  
  

Pauling Electronegativity
1.24   
36
1.30   
32

Allred Rochow Electronegativity
1.11   
29
1.20   
27

Electropositivity
  
  

Pauling Electropositivity
2.76   
18
2.70   
22

Ionization Energies
  
  

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

2nd Energy Level
1,150.00 kJ/mol   
99+
1,225.00 kJ/mol   
99+

3rd Energy Level
2,194.00 kJ/mol   
99+
2,363.00 kJ/mol   
99+

4th Energy Level
4,120.00 kJ/mol   
33
3,792.00 kJ/mol   
99+

Electrochemical Equivalent
2.08 g/amp-hr   
28
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
68   
99+
100   
18

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

Crystal Structure
Hexagonal Close Packed (HCP)   
Not Known   

Crystal Lattice
HCP-Crystal-Structure-of-Erbium.jpg#100   
Unknown-Crystal-Structure-of-Fermium.jpg#100   

Atom
  
  

Number of Protons
68   
99+
100   
18

Number of Neutrons
99   
33
157   
7

Number of Electrons
68   
99+
100   
18

Radius of an Atom
  
  

Atomic Radius
176.00 pm   
18
Not Available   

Covalent Radius
189.00 pm   
19
Not Available   

Van der Waals Radius
Not Available   
245.00 pm   
9

Atomic Weight
167.26 amu   
99+
257.00 amu   
15

Atomic Volume
18.40 cm3/mol   
25
Not Available   

Adjacent Atomic Numbers
  
  

Previous Element
Holmium
  

Next Element
Thulium
  

Valence Electron Potential
49.00 (-eV)   
29
Not Available   

Lattice Constant
355.88 pm   
39
Not Available   

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

Lattice C/A Ratio
1.57   
17
Not Available   

Mechanical Properties

Density
  
  

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

Density When Liquid (at m.p.)
8.86 g/cm3   
23
Not Available   

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)   
20
Not Available   

Elasticity properties
  
  

Shear Modulus
28.30 GPa   
25
Not Available   

Bulk Modulus
44.40 GPa   
27
Not Available   

Young's Modulus
69.90 GPa   
29
Not Available   

Poisson Ratio
0.24   
28
Not Available   

Other Mechanical Properties
Malleable   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
9.07   
32
Not Available   

Magnetic Ordering
Paramagnetic   
Unknown   

Electrical Properties
  
  

Electrical Property
Conductor   
Unknown   

Resistivity
0.86 nΩ·m   
99+
Not Available   

Electrical Conductivity
0.01 106/cm Ω   
99+
Not Available   

Electron Affinity
50.00 kJ/mol   
21
Not Available   

Thermal Properties

Specific Heat
0.17 J/(kg K)   
34
Not Available   

Molar Heat Capacity
28.12 J/mol·K   
11
Not Available   

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
12.20 µm/(m·K)   
31
Not Available   

Enthalpy
  
  

Enthalpy of Vaporization
261.00 kJ/mol   
35
Not Available   

Enthalpy of Fusion
17.20 kJ/mol   
15
Not Available   

Enthalpy of Atomization
314.00 kJ/mol   
33
Not Available   

Standard Molar Entropy
73.10 J/mol.K   
11
Not Available   

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