Symbol
Ho
  
Np
  
Group Number
Not Available
  
Not Available
  
Period Number
6
  
7
  
Block
f block
  
f block
  
Element Family
Lanthanide
  
Actinide
  
Space Group Name
P63/mmc
  
Pnma
  
Interesting Facts
- Holmium metal is very soft and malleable.
- Holmium metal is well known for its corrosion resistivity.
  
Not Available
  
Sources
Found in Minerals, Mining, Ores of Minerals
  
Made by Bombarding Uranium with Neutrons, Ores of metals
  
History
  
  
Who Discovered
Marc Delafontaine
  
Edwin McMillan and Philip H. Abelson
  
Discovery
In 1878
  
In 1940
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Not Available
  
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.
  
- Currently known uses of Neptunium metal are limited to research purpose only.
-
Neptunium’s isotope neptunium-237 is used as a neutron detectors.
  
Industrial Uses
NA
  
NA
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys, Nuclear Research
  
Alloys, Nuclear Research, Research Purposes
  
Biological Properties
  
  
Toxicity
Low Toxic
  
Toxic
  
Present in Human Body
No
  
No
  
In Blood
Not Available
  
0.00 Blood/mg dm-3
  
37
In Bone
Not Available
  
0.00 p.p.m.
  
36
Melting Point
1,461.00 °C
  
30
Boiling Point
2,600.00 °C
  
99+
3,902.00 °C
  
13
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Silver
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Brinell Hardness
Not Available
  
Vickers Hardness
Not Available
  
Speed of Sound
2,760.00 m/s
  
30
Not Available
  
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
  
Np
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
581.00 kJ/mol
  
99+
604.50 kJ/mol
  
99+
2nd Energy Level
1,140.00 kJ/mol
  
99+
1,128.00 kJ/mol
  
99+
3rd Energy Level
2,204.00 kJ/mol
  
99+
1,997.00 kJ/mol
  
99+
4th Energy Level
4,100.00 kJ/mol
  
34
3,242.00 kJ/mol
  
99+
Electrochemical Equivalent
2.02 g/amp-hr
  
29
1.77 g/amp-hr
  
39
Electron Work Function
Not Available
  
Not Available
  
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Ionization, Radioactive Isotopes, Radioactivity, Solubility
  
Electron Configuration
[Xe] 4f11 6s2
  
[Rn] 5f4 6d1 7s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Orthorhombic (ORTH)
  
Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100
  
ORTH-Crystal-Structure-of-Neptunium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
164.93 amu
  
99+
Atomic Volume
18.70 cm3/mol
  
24
11.62 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
47.90 (-eV)
  
31
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+
19.38 g/cm3
  
14
Density When Liquid (at m.p.)
Not Available
  
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile, Malleable, Sectile
  
Ductile
  
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
Not Available
  
Specific Heat
0.16 J/(kg K)
  
35
0.12 J/(kg K)
  
40
Molar Heat Capacity
27.15 J/mol·K
  
19
29.46 J/mol·K
  
8
Thermal Conductivity
16.20 W/m·K
  
99+
6.30 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
11.20 µm/(m·K)
  
35
Not Available
  
Enthalpy
  
  
Enthalpy of Vaporization
241.00 kJ/mol
  
38
Not Available
  
Enthalpy of Fusion
11.76 kJ/mol
  
29
3.20 kJ/mol
  
99+
Enthalpy of Atomization
301.00 kJ/mol
  
36
Not Available
  
Standard Molar Entropy
75.30 J/mol.K
  
8
Not Available