Symbol
Ho
  
Ir
  
Group Number
Not Available
  
Period Number
6
  
6
  
Block
f block
  
d block
  
Element Family
Lanthanide
  
Transition Metal
  
Space Group Name
P63/mmc
  
Fm_ 3m
  
Interesting Facts
- Holmium metal is very soft and malleable.
- Holmium metal is well known for its corrosion resistivity.
  
- Iridium element occurs as natural alloys of Platinum and Osmium.
- Iridium element is known as the most corrosion resistance metal .
  
Sources
Found in Minerals, Mining, Ores of Minerals
  
Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Marc Delafontaine
  
Smithson Tennant
  
Discovery
In 1878
  
In 1803
  
Abundance
  
  
Abundance In Sun
~-9999 %
  
~0.0000002 %
  
25
Abundance In Earth's Crust
Abundance In Oceans
Not Available
  
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.
  
- Iridium has an anti corrosion properties and it is used in special alloy with Osmium metal and that alloy is used in pen tips and compass bearings.
  
Industrial Uses
NA
  
Automobile Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys, Nuclear Research
  
Alloys
  
Biological Properties
  
  
Toxicity
Low Toxic
  
Toxic
  
Present in Human Body
No
  
Yes
  
Melting Point
1,461.00 °C
  
30
Boiling Point
2,600.00 °C
  
99+
4,527.00 °C
  
10
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Silvery White
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
1,670.00 MPa
  
5
Vickers Hardness
1,760.00 MPa
  
3
Speed of Sound
2,760.00 m/s
  
30
4,825.00 m/s
  
13
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Ho
  
Ir
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
581.00 kJ/mol
  
99+
880.00 kJ/mol
  
9
2nd Energy Level
1,140.00 kJ/mol
  
99+
1,600.00 kJ/mol
  
35
3rd Energy Level
2,204.00 kJ/mol
  
99+
Not Available
  
4th Energy Level
4,100.00 kJ/mol
  
34
Not Available
  
Electrochemical Equivalent
2.02 g/amp-hr
  
29
1.14 g/amp-hr
  
99+
Electron Work Function
Not Available
  
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Flammable, Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Xe] 4f11 6s2
  
[Xe] 4f14 5d7 6s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Face Centered Cubic (FCC)
  
Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100
  
FCC-Crystal-Structure-of-Iridium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
164.93 amu
  
99+
Atomic Volume
18.70 cm3/mol
  
24
9.53 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
47.90 (-eV)
  
31
140.00 (-eV)
  
5
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
8.79 g/cm3
  
99+
22.56 g/cm3
  
10
Density When Liquid (at m.p.)
Tensile Strength
Not Available
  
2,000.00 MPa
  
2
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Ductile, Malleable, Sectile
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
47.10 nΩ·m
  
99+
Electrical Conductivity
0.01 106/cm Ω
  
99+
0.19 106/cm Ω
  
10
Electron Affinity
50.00 kJ/mol
  
21
151.00 kJ/mol
  
4
Specific Heat
0.16 J/(kg K)
  
35
0.13 J/(kg K)
  
39
Molar Heat Capacity
27.15 J/mol·K
  
19
25.10 J/mol·K
  
99+
Thermal Conductivity
16.20 W/m·K
  
99+
147.00 W/m·K
  
10
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
11.20 µm/(m·K)
  
35
6.40 µm/(m·K)
  
99+
Enthalpy
  
  
Enthalpy of Vaporization
241.00 kJ/mol
  
38
799.10 kJ/mol
  
1
Enthalpy of Fusion
11.76 kJ/mol
  
29
35.23 kJ/mol
  
1
Enthalpy of Atomization
301.00 kJ/mol
  
36
837.00 kJ/mol
  
1
Standard Molar Entropy
75.30 J/mol.K
  
8
35.50 J/mol.K
  
99+