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Erbium vs Fermium

Erbium
Fermium
Fermium vs Erbium


Periodic Table
Symbol
Er  
Fm  
Group Number
3  
15
3  
15
Period Number
6  
7  
Block
f block  
f block  
Element Family
Lanthanide  
Actinide  
CAS Number
7440520  
35
7440724  
19
Space Group Name
P63/mmc  
-  
Space Group Number
194.00  
7
194.00  
7
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
0.00 %  
23
0.00 %  
35
Abundance In Sun
0.00 %  
26
0.00 %  
30
Abundance In Meteorites
0.00 %  
36
0.00 %  
99+
Abundance In Earth's Crust
0.00 %  
32
0.00 %  
99+
Abundance In Oceans
0.00 %  
36
-  
Abundance In Humans
0.00 %  
24
-  
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  
-  
Medical Uses
-  
-  
Other Uses
Alloys  
-  
Biological Properties
  
  
Toxicity
Mildly 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
1,522.00 °C  
28
1,527.00 °C  
26
Boiling Point
2,510.00 °C  
99+
0.00 °C  
99+
Appearance
  
  
Physical State
Solid  
Solid  
Color
Silvery White  
-  
Luster
Lustrous  
-  
Hardness
  
  
Mohs Hardness
1.00  
22
6.00  
6
Brinell Hardness
814.00 MPa  
12
500.00 MPa  
28
Vickers Hardness
589.00 MPa  
30
600.00 MPa  
28
Speed of Sound
2,830.00 m/s  
99+
2,500.00 m/s  
99+
Optical Properties
  
  
Refractive Index
1.76  
24
1.30  
99+
Reflectivity
36.00 %  
33
59.00 %  
24
Allotropes
No  
No  
α Allotropes
-  
-  
β Allotropes
-  
-  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Er  
Fm  
Isotopes
  
  
Known Isotopes
31  
8
18  
21
Electronegativity
  
  
Pauling Electronegativity
1.24  
37
1.30  
33
Sanderson Electronegativity
1.24  
29
1.30  
25
Allred Rochow Electronegativity
1.11  
30
1.20  
28
Mulliken-Jaffe Electronegativity
1.24  
36
1.30  
33
Allen Electronegativity
1.24  
99+
1.30  
40
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  
99+
3,792.00 kJ/mol  
99+
5th Energy Level
5,897.00 kJ/mol  
99+
6,270.00 kJ/mol  
39
6th Energy Level
5,897.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
7th Energy level
5,890.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
8th Energy Level
5,890.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
9th Energy Level
4,240.00 kJ/mol  
99+
7,040.00 kJ/mol  
33
10th Energy Level
5,890.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
11th Energy Level
5,890.00 kJ/mol  
99+
6,270.00 kJ/mol  
99+
12th Energy Level
5,890.00 kJ/mol  
99+
62,700.00 kJ/mol  
10
13th Energy Level
5,890.00 kJ/mol  
99+
6,270.00 kJ/mol  
38
14th Energy Level
5,890.00 kJ/mol  
37
6,270.00 kJ/mol  
27
15th Energy Level
58,900.00 kJ/mol  
99+
62,700.00 kJ/mol  
38
16th Energy Level
58,900.00 kJ/mol  
38
62,700.00 kJ/mol  
28
17th Energy Level
589.30 kJ/mol  
99+
627.00 kJ/mol  
99+
18th Energy Level
5,890.00 kJ/mol  
99+
6,270.00 kJ/mol  
40
19th Energy Level
589.30 kJ/mol  
99+
994.80 kJ/mol  
21
20th Energy Level
589.00 kJ/mol  
99+
627.00 kJ/mol  
99+
21st Energy Level
5,897.00 kJ/mol  
19
627.00 kJ/mol  
99+
22nd Energy Level
589.00 kJ/mol  
99+
345.00 kJ/mol  
99+
23rd Energy Level
589.30 kJ/mol  
99+
6,270.00 kJ/mol  
14
24th Energy Level
589.30 kJ/mol  
99+
627.60 kJ/mol  
38
25th Energy Level
589.00 kJ/mol  
99+
627.00 kJ/mol  
40
26th Energy Level
589.30 kJ/mol  
99+
627.60 kJ/mol  
39
27th Energy Level
589.30 kJ/mol  
99+
627.60 kJ/mol  
99+
28th Energy Level
589.30 kJ/mol  
99+
627.60 kJ/mol  
99+
29th Energy Level
589.30 kJ/mol  
99+
627.60 kJ/mol  
99+
30th Energy Level
589.70 kJ/mol  
99+
627.60 kJ/mol  
99+
Electrochemical Equivalent
2.08 g/amp-hr  
32
3.20 g/amp-hr  
15
Electron Work Function
5.93 eV  
2
4.47 eV  
21
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility  
Ionization, Radioactive Isotopes, Radioactivity  
Atomic
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  
34
157  
8
Number of Electrons
68  
99+
100  
18
Radius of an Atom
  
  
Atomic Radius
176.00 pm  
20
180.00 pm  
16
Covalent Radius
189.00 pm  
19
180.00 pm  
23
Van der Waals Radius
0.00 pm  
99+
245.00 pm  
13
Atomic Weight
167.26 amu  
99+
257.00 amu  
15
Atomic Volume
18.40 cm3/mol  
37
18.00 cm3/mol  
99+
Adjacent Atomic Numbers
  
  
Previous Element
Holmium
  
Einsteinium
  
Next Element
Thulium
  
Mendelevium
  
Valence Electron Potential
49.00 (-eV)  
30
0.00 (-eV)  
99+
Lattice Constant
355.88 pm  
99+
350.00 pm  
99+
Lattice Angles
π/2, π/2, 2 π/3  
-  
Lattice C/A Ratio
1.57  
40
1.63  
13
Mechanical
Density
  
  
Density At Room Temperature
9.07 g/cm3  
99+
9.70 g/cm3  
99+
Density When Liquid (at m.p.)
8.86 g/cm3  
99+
9.70 g/cm3  
99+
Tensile Strength
350.00 MPa  
12
0.10 MPa  
99+
Viscosity
0.00  
25
0.00  
25
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
21
0.00 (Pa)  
22
Vapor Pressure at 2000 K
0.00 (Pa)  
30
0.00 (Pa)  
30
Elasticity properties
  
  
Shear Modulus
28.30 GPa  
31
30.00 GPa  
27
Bulk Modulus
44.40 GPa  
31
50.00 GPa  
24
Young's Modulus
69.90 GPa  
31
0.00 GPa  
99+
Poisson Ratio
0.24  
28
0.35  
9
Other Mechanical Properties
Malleable  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
9.07  
99+
9.70  
99+
Magnetic Ordering
Paramagnetic  
-  
Permeability
0.00 H/m  
17
0.00 H/m  
16
Susceptibility
0.00  
11
0.00  
24
Electrical Properties
  
  
Electrical Property
Conductor  
-  
Resistivity
0.86 nΩ·m  
99+
7.90 nΩ·m  
99+
Electrical Conductivity
0.01 106/cm Ω  
99+
0.00 106/cm Ω  
99+
Electron Affinity
50.00 kJ/mol  
26
0.00 kJ/mol  
99+
Thermal
Specific Heat
0.17 J/(kg K)  
35
0.10 J/(kg K)  
99+
Molar Heat Capacity
28.12 J/mol·K  
14
27.00 J/mol·K  
29
Thermal Conductivity
14.50 W/m·K  
99+
0.00 W/m·K  
99+
Critical Temperature
1,802.00 K  
30
1,323.00 K  
99+
Thermal Expansion
12.20 µm/(m·K)  
99+
11.00 µm/(m·K)  
99+
Enthalpy
  
  
Enthalpy of Vaporization
261.00 kJ/mol  
99+
319.20 kJ/mol  
99+
Enthalpy of Fusion
17.20 kJ/mol  
15
13.30 kJ/mol  
30
Enthalpy of Atomization
314.00 kJ/mol  
99+
-  
Standard Molar Entropy
73.10 J/mol.K  
11
50.00 J/mol.K  
99+
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