Holmium Chromium Comparison
Periodic Table
Symbol
Ho
Cr
Group Number
Not Available
6
12
Period Number
6
4
Block
f block
d block
Element Family
Lanthanide
Transition Metal
CAS Number
7440600
29
7440473
39
Space Group Name
P63/mmc
Im_ 3m
Space Group Number
194.00
5
229.00
1
Facts
Interesting Facts
- Holmium metal is very soft and malleable.
- Holmium metal is well known for its corrosion resistivity.
- Chromium is highly reactive, hence it is not found free in nature.
- Ores of Chromites mineral are the major source of Chromium metal.
- Almost 90% leather tanning is done with the help of chromium.
Sources
Found in Minerals, Mining, Ores of Minerals
Found in Minerals, Mining, Ores of metals, Ores of Minerals
History
Who Discovered
Marc Delafontaine
Louis Nicolas Vauquelin
Discovery
In 1878
In Between 1797 - 1798
Abundance
Abundance In Universe
5 * 10-8 %
27
1.5 * 10-3 %
7
Abundance In Sun
~-9999 %
~0.002 %
7
Abundance In Meteorites
0.00 %
99+
0.30 %
7
Abundance In Earth's Crust
0.00 %
38
0.01 %
13
Abundance In Oceans
0.00 %
99+
0.00 %
16
Abundance In Humans
Not Available
0.00 %
16
Uses
Uses & Benefits
- 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.
- It is used to harden the steel and produces a stainless steel and other various alloys.
- It is also used to give proper finish to polished mirrors. Its chromium plates are used in bathroom fittings.
Industrial Uses
NA
Automobile Industry, Chemical Industry
Medical Uses
NA
NA
Other Uses
Alloys, Nuclear Research
Alloys
Biological Properties
Toxicity
Low Toxic
Highly Toxic
Present in Human Body
No
Yes
In Blood
Not Available
0.11 Blood/mg dm-3
12
In Bone
Not Available
0.33 p.p.m.
21
Physical Properties
Melting Point
1,461.00 °C
30
1,857.00 °C
14
Boiling Point
2,600.00 °C
99+
2,672.00 °C
39
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silver
Luster
Metallic
Metallic
Hardness
Mohs Hardness
Not Available
8.50
1
Brinell Hardness
746.00 MPa
13
687.00 MPa
16
Vickers Hardness
481.00 MPa
23
1,060.00 MPa
10
Speed of Sound
2,760.00 m/s
30
5,940.00 m/s
5
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
Ho
Cr
Isotopes
Known Isotopes
34
5
21
18
Electronegativity
Pauling Electronegativity
1.23
37
1.66
18
Sanderson Electronegativity
Not Available
1.66
14
Allred Rochow Electronegativity
1.10
30
1.56
10
Allen Electronegativity
Not Available
1.65
19
Electropositivity
Pauling Electropositivity
2.77
17
2.34
36
Ionization Energies
1st Energy Level
581.00 kJ/mol
99+
26,130.00 kJ/mol
1
2nd Energy Level
1,140.00 kJ/mol
99+
28,750.00 kJ/mol
1
3rd Energy Level
2,204.00 kJ/mol
99+
34,230.00 kJ/mol
1
4th Energy Level
4,100.00 kJ/mol
34
37,066.00 kJ/mol
1
5th Energy Level
Not Available
97,510.00 kJ/mol
1
6th Energy Level
Not Available
105,800.00 kJ/mol
1
7th Energy level
Not Available
114,300.00 kJ/mol
1
8th Energy Level
Not Available
125,300.00 kJ/mol
1
9th Energy Level
Not Available
134,700.00 kJ/mol
1
10th Energy Level
Not Available
144,300.00 kJ/mol
1
11th Energy Level
Not Available
26,130.00 kJ/mol
12
12th Energy Level
Not Available
28,750.00 kJ/mol
13
13th Energy Level
Not Available
34,230.00 kJ/mol
10
14th Energy Level
Not Available
37,066.00 kJ/mol
12
15th Energy Level
Not Available
97,510.00 kJ/mol
1
16th Energy Level
Not Available
105,800.00 kJ/mol
2
17th Energy Level
Not Available
114,300.00 kJ/mol
3
18th Energy Level
Not Available
125,300.00 kJ/mol
4
19th Energy Level
Not Available
134,700.00 kJ/mol
5
20th Energy Level
Not Available
144,300.00 kJ/mol
7
21st Energy Level
Not Available
157,700.00 kJ/mol
7
22nd Energy Level
Not Available
166,090.00 kJ/mol
6
Electrochemical Equivalent
2.02 g/amp-hr
29
0.32 g/amp-hr
99+
Electron Work Function
Not Available
4.50 eV
14
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
67
99+
24
99+
Electron Configuration
[Xe] 4f11 6s2
[Ar] 3d5 4s1
Crystal Structure
Hexagonal Close Packed (HCP)
Body Centered Cubic (BCC)
Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
67
99+
24
99+
Number of Neutrons
98
34
28
99+
Number of Electrons
67
99+
24
99+
Radius of an Atom
Atomic Radius
176.00 pm
18
128.00 pm
99+
Covalent Radius
192.00 pm
17
139.00 pm
99+
Van der Waals Radius
216.00 pm
24
200.00 pm
28
Atomic Weight
164.93 amu
99+
52.00 amu
99+
Atomic Volume
18.70 cm3/mol
24
7.23 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
47.90 (-eV)
31
170.00 (-eV)
4
Lattice Constant
357.73 pm
38
291.00 pm
99+
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, π/2
Lattice C/A Ratio
1.57
17
Not Available
Mechanical Properties
Density
Density At Room Temperature
8.79 g/cm3
99+
7.19 g/cm3
99+
Density When Liquid (at m.p.)
8.34 g/cm3
26
6.30 g/cm3
40
Tensile Strength
Not Available
689.00 MPa
7
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)
16
0.00 (Pa)
24
Vapor Pressure at 2000 K
Not Available
774.00 (Pa)
1
Elasticity properties
Shear Modulus
26.30 GPa
28
115.00 GPa
9
Bulk Modulus
40.20 GPa
32
160.00 GPa
11
Young's Modulus
64.80 GPa
31
279.00 GPa
8
Poisson Ratio
0.23
29
0.21
32
Other Mechanical Properties
Ductile, Malleable, Sectile
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
8.80
35
7.19
99+
Magnetic Ordering
Paramagnetic
Antiferromagnetic
Electrical Properties
Electrical Property
Conductor
NA
Resistivity
814.00 nΩ·m
4
125.00 nΩ·m
27
Electrical Conductivity
0.01 106/cm Ω
99+
0.08 106/cm Ω
25
Electron Affinity
50.00 kJ/mol
21
64.30 kJ/mol
15
Thermal Properties
Specific Heat
0.16 J/(kg K)
35
0.45 J/(kg K)
12
Molar Heat Capacity
27.15 J/mol·K
19
23.35 J/mol·K
99+
Thermal Conductivity
16.20 W/m·K
99+
93.90 W/m·K
17
Critical Temperature
Not Available
Not Available
Thermal Expansion
11.20 µm/(m·K)
35
4.90 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
241.00 kJ/mol
38
348.80 kJ/mol
24
Enthalpy of Fusion
11.76 kJ/mol
29
15.31 kJ/mol
20
Enthalpy of Atomization
301.00 kJ/mol
36
397.50 kJ/mol
21
Standard Molar Entropy
75.30 J/mol.K
8
23.80 J/mol.K
99+
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