Symbol
Ho
  
Sm
  
Group Number
Not Available
  
Not Available
  
Period Number
6
  
6
  
Block
f block
  
f block
  
Element Family
Lanthanide
  
Lanthanide
  
Space Group Name
P63/mmc
  
R_ 3m
  
Interesting Facts
- Holmium metal is very soft and malleable.
- Holmium metal is well known for its corrosion resistivity.
  
- Samarium metals helps stimulating body metabolism.
- Samarium metals was 1st observed by Jean Charles Galissard de Marignac in Dydimia in 1853.
  
Sources
Found in Minerals, Mining, Ores of Minerals
  
Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Marc Delafontaine
  
Lecoq de Boisbaudran
  
Discovery
In 1878
  
In 1879
  
Abundance
  
  
Abundance In Sun
~-9999 %
  
~0.0000001 %
  
26
Abundance In Earth's Crust
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.
  
- Magnets of Samarium cobalt alloy are stronger than that of Iron and hence, they are used in microwave application.
- Samarium metal also used in optical lasers and infrared absorbing glasses and as a neutron absorber.
  
Industrial Uses
NA
  
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys, Nuclear Research
  
Alloys, In Nuclear Reactors
  
Biological Properties
  
  
Toxicity
Low Toxic
  
Slightly Toxic
  
Present in Human Body
No
  
Yes
  
In Blood
Not Available
  
0.01 Blood/mg dm-3
  
22
Melting Point
1,461.00 °C
  
30
1,072.00 °C
  
99+
Boiling Point
2,600.00 °C
  
99+
1,900.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Silvery White
  
Luster
Metallic
  
Lustrous
  
Hardness
  
  
Speed of Sound
2,760.00 m/s
  
30
2,130.00 m/s
  
99+
Optical Properties
  
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Ho
  
Sm
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
581.00 kJ/mol
  
99+
544.50 kJ/mol
  
99+
2nd Energy Level
1,140.00 kJ/mol
  
99+
1,070.00 kJ/mol
  
99+
3rd Energy Level
2,204.00 kJ/mol
  
99+
2,260.00 kJ/mol
  
99+
4th Energy Level
4,100.00 kJ/mol
  
34
3,990.00 kJ/mol
  
37
Electrochemical Equivalent
2.02 g/amp-hr
  
29
1.87 g/amp-hr
  
34
Electron Work Function
Not Available
  
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Ionization, Radioactive Isotopes
  
Electron Configuration
[Xe] 4f11 6s2
  
[Xe] 4f6 6s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Rhombohedral (RHO)
  
Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100
  
RHO-Crystal-Structure-of-Samarium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
164.93 amu
  
99+
150.36 amu
  
99+
Atomic Volume
18.70 cm3/mol
  
24
19.95 cm3/mol
  
19
Adjacent Atomic Numbers
  
  
Valence Electron Potential
47.90 (-eV)
  
31
44.80 (-eV)
  
37
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, 2 π/3
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
8.79 g/cm3
  
99+
7.52 g/cm3
  
99+
Density When Liquid (at m.p.)
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Other Mechanical Properties
Ductile, Malleable, Sectile
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
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
Specific Heat
0.16 J/(kg K)
  
35
0.20 J/(kg K)
  
31
Molar Heat Capacity
27.15 J/mol·K
  
19
29.54 J/mol·K
  
7
Thermal Conductivity
16.20 W/m·K
  
99+
13.30 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
11.20 µm/(m·K)
  
35
12.70 µm/(m·K)
  
30
Enthalpy
  
  
Enthalpy of Vaporization
241.00 kJ/mol
  
38
166.40 kJ/mol
  
99+
Enthalpy of Fusion
11.76 kJ/mol
  
29
8.62 kJ/mol
  
40
Enthalpy of Atomization
301.00 kJ/mol
  
36
209.00 kJ/mol
  
99+
Standard Molar Entropy
75.30 J/mol.K
  
8
69.60 J/mol.K
  
15