Erbium Holmium Comparison
Periodic Table
Symbol
Er
Ho
Group Number
Not Available
Not Available
Period Number
6
6
Block
f block
f block
Element Family
Lanthanide
Lanthanide
CAS Number
7440520
35
7440600
29
Space Group Name
P63/mmc
P63/mmc
Space Group Number
194.00
5
194.00
5
Facts
Interesting Facts
- Erbium metal is used as alloyed with Vanadium to make it softer.
- Recent studies shows that it is helpful for metabolism.
- Holmium metal is very soft and malleable.
- Holmium metal is well known for its corrosion resistivity.
Sources
Mining
Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Carl Gustaf Mosander
Marc Delafontaine
Discovery
In 1842
In 1878
Abundance
Abundance In Universe
2 * 10-7 %
22
5 * 10-8 %
27
Abundance In Sun
~0.0000001 %
26
~-9999 %
Abundance In Meteorites
0.00 %
36
0.00 %
99+
Abundance In Earth's Crust
0.00 %
32
0.00 %
38
Abundance In Oceans
0.00 %
36
0.00 %
99+
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.
- Holmium metal has an ability to absorb neutrons, so this metal is used in nuclear reactors to keep the chain reactions of elements under control.
- Alloys of Holmium are used to produce Magnet.
Industrial Uses
Chemical Industry
NA
Medical Uses
NA
NA
Other Uses
Alloys
Alloys, Nuclear Research
Biological Properties
Toxicity
Mildly Toxic
Low Toxic
Present in Human Body
No
No
Physical Properties
Melting Point
1,522.00 °C
28
1,461.00 °C
30
Boiling Point
2,510.00 °C
99+
2,600.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery White
Luster
Lustrous
Metallic
Hardness
Brinell Hardness
814.00 MPa
11
746.00 MPa
13
Vickers Hardness
589.00 MPa
19
481.00 MPa
23
Speed of Sound
2,830.00 m/s
28
2,760.00 m/s
30
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
Ho
Isotopes
Known Isotopes
31
8
34
5
Electronegativity
Pauling Electronegativity
1.24
36
1.23
37
Allred Rochow Electronegativity
1.11
29
1.10
30
Electropositivity
Pauling Electropositivity
2.76
18
2.77
17
Ionization Energies
1st Energy Level
589.30 kJ/mol
99+
581.00 kJ/mol
99+
2nd Energy Level
1,150.00 kJ/mol
99+
1,140.00 kJ/mol
99+
3rd Energy Level
2,194.00 kJ/mol
99+
2,204.00 kJ/mol
99+
4th Energy Level
4,120.00 kJ/mol
33
4,100.00 kJ/mol
34
Electrochemical Equivalent
2.08 g/amp-hr
28
2.02 g/amp-hr
29
Electron Work Function
Not Available
Not Available
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
68
99+
67
99+
Electron Configuration
[Xe] 4f12 6s2
[Xe] 4f11 6s2
Crystal Structure
Hexagonal Close Packed (HCP)
Hexagonal Close Packed (HCP)
Crystal Lattice
HCP-Crystal-Structure-of-Erbium.jpg#100
HCP-Crystal-Structure-of-Holmium.jpg#100
Atom
Number of Protons
68
99+
67
99+
Number of Neutrons
99
33
98
34
Number of Electrons
68
99+
67
99+
Radius of an Atom
Atomic Radius
176.00 pm
18
176.00 pm
18
Covalent Radius
189.00 pm
19
192.00 pm
17
Van der Waals Radius
Not Available
216.00 pm
24
Atomic Weight
167.26 amu
99+
164.93 amu
99+
Atomic Volume
18.40 cm3/mol
25
18.70 cm3/mol
24
Adjacent Atomic Numbers
Valence Electron Potential
49.00 (-eV)
29
47.90 (-eV)
31
Lattice Constant
355.88 pm
39
357.73 pm
38
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.57
17
1.57
17
Mechanical Properties
Density
Density At Room Temperature
9.07 g/cm3
99+
8.79 g/cm3
99+
Density When Liquid (at m.p.)
8.86 g/cm3
23
8.34 g/cm3
26
Tensile Strength
Not Available
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)
20
0.00 (Pa)
16
Elasticity properties
Shear Modulus
28.30 GPa
25
26.30 GPa
28
Bulk Modulus
44.40 GPa
27
40.20 GPa
32
Young's Modulus
69.90 GPa
29
64.80 GPa
31
Poisson Ratio
0.24
28
0.23
29
Other Mechanical Properties
Malleable
Ductile, Malleable, Sectile
Magnetic Properties
Magnetic Characteristics
Specific Gravity
9.07
32
8.80
35
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
0.86 nΩ·m
99+
814.00 nΩ·m
4
Electrical Conductivity
0.01 106/cm Ω
99+
0.01 106/cm Ω
99+
Electron Affinity
50.00 kJ/mol
21
50.00 kJ/mol
21
Thermal Properties
Specific Heat
0.17 J/(kg K)
34
0.16 J/(kg K)
35
Molar Heat Capacity
28.12 J/mol·K
11
27.15 J/mol·K
19
Thermal Conductivity
14.50 W/m·K
99+
16.20 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
12.20 µm/(m·K)
31
11.20 µm/(m·K)
35
Enthalpy
Enthalpy of Vaporization
261.00 kJ/mol
35
241.00 kJ/mol
38
Enthalpy of Fusion
17.20 kJ/mol
15
11.76 kJ/mol
29
Enthalpy of Atomization
314.00 kJ/mol
33
301.00 kJ/mol
36
Standard Molar Entropy
73.10 J/mol.K
11
75.30 J/mol.K
8
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