Symbol
Nb
  
Ho
  
Group Number
Not Available
  
Period Number
5
  
6
  
Block
d block
  
f block
  
Element Family
Transition Metal
  
Lanthanide
  
Space Group Name
Im_ 3m
  
P63/mmc
  
Interesting Facts
- Niobium metal was used to get called Columbium in past.
- Niobium metal found freely in nature (abundance).
  
- Holmium metal is very soft and malleable.
- Holmium metal is well known for its corrosion resistivity.
  
Sources
By-product of Tin Extraction, Found in Minerals, Mining, Ores of Minerals
  
Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Charles Hatchett
  
Marc Delafontaine
  
Discovery
In 1801
  
In 1878
  
Abundance
  
  
Abundance In Sun
~0.0000004 %
  
23
~-9999 %
  
Abundance In Earth's Crust
Uses & Benefits
- Niobium alloys are used in jet engines and rockets and spacecraft, beams and girders for buildings and oil and gas pipelines.
- It is used superconducting magnets in particles accelerators, NMR and MRI equipment.
  
- 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
Aerospace Industry, Ammunition Industry, Electrical Industry, Electronic Industry
  
NA
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys
  
Alloys, Nuclear Research
  
Biological Properties
  
  
Toxicity
Low Toxic
  
Low Toxic
  
Present in Human Body
Yes
  
No
  
In Blood
0.01 Blood/mg dm-3
  
25
Not Available
  
In Bone
0.07 p.p.m.
  
25
Not Available
  
Melting Point
1,461.00 °C
  
30
Boiling Point
2,468.00 °C
  
99+
2,600.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Silvery White
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
Speed of Sound
3,480.00 m/s
  
21
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 Formula
Nb
  
Ho
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
652.10 kJ/mol
  
99+
581.00 kJ/mol
  
99+
2nd Energy Level
1,380.00 kJ/mol
  
99+
1,140.00 kJ/mol
  
99+
3rd Energy Level
2,416.00 kJ/mol
  
99+
2,204.00 kJ/mol
  
99+
4th Energy Level
3,700.00 kJ/mol
  
99+
4,100.00 kJ/mol
  
34
5th Energy Level
4,877.00 kJ/mol
  
36
Not Available
  
6th Energy Level
9,847.00 kJ/mol
  
11
Not Available
  
7th Energy level
12,100.00 kJ/mol
  
14
Not Available
  
Electrochemical Equivalent
0.69 g/amp-hr
  
99+
2.02 g/amp-hr
  
29
Electron Work Function
Not Available
  
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Kr] 4d4 5s1
  
[Xe] 4f11 6s2
  
Crystal Structure
Body Centered Cubic (BCC)
  
Hexagonal Close Packed (HCP)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
HCP-Crystal-Structure-of-Holmium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
164.93 amu
  
99+
Atomic Volume
10.87 cm3/mol
  
99+
18.70 cm3/mol
  
24
Adjacent Atomic Numbers
  
  
Valence Electron Potential
104.00 (-eV)
  
8
47.90 (-eV)
  
31
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, 2 π/3
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
8.57 g/cm3
  
99+
8.79 g/cm3
  
99+
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
  
  
Other Mechanical Properties
Ductile, Malleable
  
Ductile, Malleable, Sectile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
152.00 nΩ·m
  
23
Electrical Conductivity
0.07 106/cm Ω
  
28
0.01 106/cm Ω
  
99+
Electron Affinity
86.10 kJ/mol
  
12
50.00 kJ/mol
  
21
Specific Heat
0.26 J/(kg K)
  
20
0.16 J/(kg K)
  
35
Molar Heat Capacity
24.60 J/mol·K
  
99+
27.15 J/mol·K
  
19
Thermal Conductivity
53.70 W/m·K
  
29
16.20 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
7.30 µm/(m·K)
  
99+
11.20 µm/(m·K)
  
35
Enthalpy
  
  
Enthalpy of Vaporization
696.60 kJ/mol
  
4
241.00 kJ/mol
  
38
Enthalpy of Fusion
27.20 kJ/mol
  
6
11.76 kJ/mol
  
29
Enthalpy of Atomization
745.00 kJ/mol
  
4
301.00 kJ/mol
  
36
Standard Molar Entropy
36.40 J/mol.K
  
99+
75.30 J/mol.K
  
8