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Fermium Terbium Comparison


Terbium Fermium comparison


Periodic Table

Symbol
Fm   
Tb   

Group Number
Not Available   
Not Available   

Period Number
7   
6   

Block
f block   
f block   

Element Family
Actinide   
Lanthanide   

CAS Number
7440724   
19
7440279   
99+

Space Group Name
Not Available   
P63/mmc   

Space Group Number
Not Available   
194.00   
5

Facts

Interesting Facts
  • Fermium metal is highly radioactive in nature.
  • Fermium is synthetically produced metal.
  
  • At times Terbium metal acts same as Calcium.
  • Terbium metal closely similar to Lanthanum metal.
  

Sources
Bombarding Pu-239 with Neutrons   
Found in Minerals, Found with Other Rare Earth Metals, Mining, Ores of Minerals   

History
  
  

Who Discovered
Lawrence Berkeley National Laboratory   
Carl Gustaf Mosander   

Discovery
In 1952   
In 1842   

Abundance
  
  

Abundance In Universe
Not Available   
5 * 10-8 %   
27

Abundance In Sun
~-9999 %   
~0.00000001 %   
29

Abundance In Meteorites
Not Available   
0.00 %   
99+

Abundance In Earth's Crust
Not Available   
0.00 %   
40

Abundance In Oceans
Not Available   
0.00 %   
99+

Uses

Uses & Benefits
  • Currently known uses of Fermium metal are limited to research purpose only.
  
  • Terbium salts are used in optical devices like laser devices.
  • Terbium’s alloy lengthens and shortens the magnetic field and this effect forms loudspeaker.
  

Industrial Uses
NA   
Electronic Industry   

Medical Uses
NA   
NA   

Other Uses
NA   
Alloys   

Biological Properties
  
  

Toxicity
Unknown   
Low Toxic   

Present in Human Body
No   
No   

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

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

Physical Properties

Melting Point
1,527.00 °C   
26
1,356.00 °C   
33

Boiling Point
Not Available   
3,123.00 °C   
29

Appearance
  
  

Physical State
Solid   
Solid   

Color
Unknown   
Silvery White   

Luster
Not Defined   
Metallic   

Hardness
  
  

Brinell Hardness
Not Available   
677.00 MPa   
17

Vickers Hardness
Not Available   
863.00 MPa   
13

Speed of Sound
Not Available   
2,620.00 m/s   
35

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
Fm   
Tb   

Isotopes
  
  

Known Isotopes
18   
21
26   
13

Electronegativity
  
  

Pauling Electronegativity
1.30   
32
Not Available   

Allred Rochow Electronegativity
1.20   
27
1.10   
30

Electropositivity
  
  

Pauling Electropositivity
2.70   
22
Not Available   

Ionization Energies
  
  

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

2nd Energy Level
1,225.00 kJ/mol   
99+
1,174.80 kJ/mol   
99+

3rd Energy Level
2,363.00 kJ/mol   
99+
2,417.00 kJ/mol   
99+

4th Energy Level
3,792.00 kJ/mol   
99+
4,203.00 kJ/mol   
31

Electrochemical Equivalent
3.20 g/amp-hr   
13
1.98 g/amp-hr   
31

Electron Work Function
Not Available   
3.00 eV   
36

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

Atomic Properties

Atomic Number
100   
18
65   
99+

Electron Configuration
[Rn] 5f12 7s2   
[Xe] 4f9 6s2   

Crystal Structure
Not Known   
Hexagonal Close Packed (HCP)   

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

Atom
  
  

Number of Protons
100   
18
65   
99+

Number of Neutrons
157   
7
94   
36

Number of Electrons
100   
18
65   
99+

Radius of an Atom
  
  

Atomic Radius
Not Available   
177.00 pm   
17

Covalent Radius
Not Available   
194.00 pm   
16

Van der Waals Radius
245.00 pm   
9
221.00 pm   
22

Atomic Weight
257.00 amu   
15
158.93 amu   
99+

Atomic Volume
Not Available   
19.20 cm3/mol   
22

Adjacent Atomic Numbers
  
  

Previous Element
Gadolinium
  

Next Element
Dysprosium
  

Valence Electron Potential
Not Available   
46.80 (-eV)   
33

Lattice Constant
Not Available   
360.10 pm   
36

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

Lattice C/A Ratio
Not Available   
1.58   
13

Mechanical Properties

Density
  
  

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

Density When Liquid (at m.p.)
Not Available   
7.65 g/cm3   
30

Tensile Strength
Not Available   
60.00 MPa   
17

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
Not Available   
0.00 (Pa)   
29

Vapor Pressure at 2000 K
Not Available   
12.50 (Pa)   
8

Elasticity properties
  
  

Shear Modulus
Not Available   
22.10 GPa   
32

Bulk Modulus
Not Available   
38.70 GPa   
33

Young's Modulus
Not Available   
55.70 GPa   
34

Poisson Ratio
Not Available   
0.26   
21

Other Mechanical Properties
NA   
Ductile, Malleable   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
Not Available   
8.23   
39

Magnetic Ordering
Unknown   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Unknown   
Conductor   

Resistivity
Not Available   
1.15 nΩ·m   
99+

Electrical Conductivity
Not Available   
0.01 106/cm Ω   
99+

Electron Affinity
Not Available   
50.00 kJ/mol   
21

Thermal Properties

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

Molar Heat Capacity
Not Available   
28.91 J/mol·K   
9

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
Not Available   
10.30 µm/(m·K)   
38

Enthalpy
  
  

Enthalpy of Vaporization
Not Available   
330.90 kJ/mol   
26

Enthalpy of Fusion
Not Available   
10.80 kJ/mol   
34

Enthalpy of Atomization
Not Available   
314.00 kJ/mol   
33

Standard Molar Entropy
Not Available   
73.20 J/mol.K   
10

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