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Holmium vs Protactinium

Holmium
Protactinium
Protactinium vs Holmium


Periodic Table
Symbol
Ho   
Pa   
Group Number
Not Available   
Not Available   
Period Number
6   
7   
Block
f block   
f block   
Element Family
Lanthanide   
Actinide   
CAS Number
7440600   
29
7440133   
99+
Space Group Name
P63/mmc   
I4/mmm   
Space Group Number
194.00   
5
139.00   
8
Facts
Interesting Facts
  • Holmium metal is very soft and malleable.
  • Holmium metal is well known for its corrosion resistivity.
  
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  
Sources
Found in Minerals, Mining, Ores of Minerals   
Found in Uranium Ores, Mining, Ores of metals   
History
  
  
Who Discovered
Marc Delafontaine   
William Crookes   
Discovery
In 1878   
In 1900   
Abundance
  
  
Abundance In Universe
5 * 10-8 %   
27
Not Available   
Abundance In Meteorites
0.00 %   
99+
Not Available   
Abundance In Earth's Crust
0.00 %   
38
0.00 %   
99+
Abundance In Oceans
0.00 %   
99+
0.00 %   
99+
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.
  
  • Currently known uses of Protactinium metal are limited to research purpose only.
  
Industrial Uses
NA   
NA   
Medical Uses
NA   
NA   
Other Uses
Alloys, Nuclear Research   
NA   
Biological Properties
  
  
Toxicity
Low Toxic   
Highly 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
Physical Properties
Melting Point
1,461.00 °C   
30
1,568.00 °C   
21
Boiling Point
2,600.00 °C   
99+
4,027.00 °C   
12
Appearance
  
  
Physical State
Solid   
Solid   
Color
Silvery White   
Silver   
Luster
Metallic   
Metallic   
Hardness
  
  
Brinell Hardness
746.00 MPa   
13
Not Available   
Vickers Hardness
481.00 MPa   
23
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 Properties
Chemical Formula
Ho   
Pa   
Isotopes
  
  
Known Isotopes
34   
5
27   
12
Electronegativity
  
  
Pauling Electronegativity
1.23   
37
1.50   
27
Allred Rochow Electronegativity
1.10   
30
1.14   
28
Electropositivity
  
  
Pauling Electropositivity
2.77   
17
2.50   
27
Ionization Energies
  
  
1st Energy Level
581.00 kJ/mol   
99+
568.00 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+
1,814.00 kJ/mol   
99+
4th Energy Level
4,100.00 kJ/mol   
34
2,991.00 kJ/mol   
99+
Electrochemical Equivalent
2.02 g/amp-hr   
29
1.72 g/amp-hr   
99+
Electron Work Function
Not Available   
Not Available   
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility   
Ionization, Radioactive Isotopes, Radioactivity   
Atomic Properties
Atomic Number
67   
99+
91   
27
Electron Configuration
[Xe] 4f11 6s2   
[Rn] 5f2 6d1 7s2   
Crystal Structure
Hexagonal Close Packed (HCP)   
Tetragonal (TETR)   
Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100   
TETR-Crystal-Structure-of-Protactinium.jpg#100   
Atom
  
  
Number of Protons
67   
99+
91   
27
Number of Neutrons
98   
34
122   
21
Number of Electrons
67   
99+
91   
27
Radius of an Atom
  
  
Atomic Radius
176.00 pm   
18
163.00 pm   
25
Covalent Radius
192.00 pm   
17
200.00 pm   
11
Van der Waals Radius
216.00 pm   
24
243.00 pm   
11
Atomic Weight
164.93 amu   
99+
231.04 amu   
24
Atomic Volume
18.70 cm3/mol   
24
15.00 cm3/mol   
34
Adjacent Atomic Numbers
  
  
Previous Element
Dysprosium
  
Thorium
  
Next Element
Erbium
  
Uranium
  
Valence Electron Potential
47.90 (-eV)   
31
92.00 (-eV)   
11
Lattice Constant
357.73 pm   
38
392.50 pm   
23
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+
15.37 g/cm3   
20
Density When Liquid (at m.p.)
8.34 g/cm3   
26
Not Available   
Tensile Strength
Not Available   
Not Available   
Viscosity
Not Available   
Not Available   
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)   
16
Not Available   
Elasticity properties
  
  
Shear Modulus
26.30 GPa   
28
Not Available   
Bulk Modulus
40.20 GPa   
32
Not Available   
Young's Modulus
64.80 GPa   
31
Not Available   
Poisson Ratio
0.23   
29
Not Available   
Other Mechanical Properties
Ductile, Malleable, Sectile   
Unknown   
Magnetic Properties
Magnetic Characteristics
  
  
Specific Gravity
8.80   
35
15.37   
12
Magnetic Ordering
Paramagnetic   
Paramagnetic   
Electrical Properties
  
  
Electrical Property
Conductor   
Conductor   
Resistivity
814.00 nΩ·m   
4
177.00 nΩ·m   
21
Electrical Conductivity
0.01 106/cm Ω   
99+
0.05 106/cm Ω   
34
Electron Affinity
50.00 kJ/mol   
21
Not Available   
Thermal Properties
Specific Heat
0.16 J/(kg K)   
35
0.12 J/(kg K)   
40
Molar Heat Capacity
27.15 J/mol·K   
19
Not Available   
Thermal Conductivity
16.20 W/m·K   
99+
47.00 W/m·K   
32
Critical Temperature
Not Available   
Not Available   
Thermal Expansion
11.20 µm/(m·K)   
35
9.90 µm/(m·K)   
40
Enthalpy
  
  
Enthalpy of Vaporization
241.00 kJ/mol   
38
Not Available   
Enthalpy of Fusion
11.76 kJ/mol   
29
12.34 kJ/mol   
28
Enthalpy of Atomization
301.00 kJ/mol   
36
Not Available   
Standard Molar Entropy
75.30 J/mol.K   
8
198.10 J/mol.K   
1
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