Home
 Compare Metals

Protactinium vs Holmium

Protactinium
Holmium
Holmium vs Protactinium


Periodic Table
Symbol
Pa   
Ho   
Group Number
Not Available   
Not Available   
Period Number
7   
6   
Block
f block   
f block   
Element Family
Actinide   
Lanthanide   
CAS Number
7440133   
99+
7440600   
29
Space Group Name
I4/mmm   
P63/mmc   
Space Group Number
139.00   
8
194.00   
5
Facts
Interesting Facts
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  
  • Holmium metal is very soft and malleable.
  • Holmium metal is well known for its corrosion resistivity.
  
Sources
Found in Uranium Ores, Mining, Ores of metals   
Found in Minerals, Mining, Ores of Minerals   
History
  
  
Who Discovered
William Crookes   
Marc Delafontaine   
Discovery
In 1900   
In 1878   
Abundance
  
  
Abundance In Universe
Not Available   
5 * 10-8 %   
27
Abundance In Meteorites
Not Available   
0.00 %   
99+
Abundance In Earth's Crust
0.00 %   
99+
0.00 %   
38
Abundance In Oceans
0.00 %   
99+
0.00 %   
99+
Uses
Uses & Benefits
  • Currently known uses of Protactinium metal are limited to research purpose only.
  
  • 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
NA   
NA   
Medical Uses
NA   
NA   
Other Uses
NA   
Alloys, Nuclear Research   
Biological Properties
  
  
Toxicity
Highly Toxic   
Low Toxic   
Present in Human Body
No   
No   
In Blood
0.00 Blood/mg dm-3   
37
Not Available   
In Bone
0.00 p.p.m.   
36
Not Available   
Physical Properties
Melting Point
1,568.00 °C   
21
1,461.00 °C   
30
Boiling Point
4,027.00 °C   
12
2,600.00 °C   
99+
Appearance
  
  
Physical State
Solid   
Solid   
Color
Silver   
Silvery White   
Luster
Metallic   
Metallic   
Hardness
  
  
Brinell Hardness
Not Available   
746.00 MPa   
13
Vickers Hardness
Not Available   
481.00 MPa   
23
Speed of Sound
Not Available   
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 Properties
Chemical Formula
Pa   
Ho   
Isotopes
  
  
Known Isotopes
27   
12
34   
5
Electronegativity
  
  
Pauling Electronegativity
1.50   
27
1.23   
37
Allred Rochow Electronegativity
1.14   
28
1.10   
30
Electropositivity
  
  
Pauling Electropositivity
2.50   
27
2.77   
17
Ionization Energies
  
  
1st Energy Level
568.00 kJ/mol   
99+
581.00 kJ/mol   
99+
2nd Energy Level
1,128.00 kJ/mol   
99+
1,140.00 kJ/mol   
99+
3rd Energy Level
1,814.00 kJ/mol   
99+
2,204.00 kJ/mol   
99+
4th Energy Level
2,991.00 kJ/mol   
99+
4,100.00 kJ/mol   
34
Electrochemical Equivalent
1.72 g/amp-hr   
99+
2.02 g/amp-hr   
29
Electron Work Function
Not Available   
Not Available   
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity   
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility   
Atomic Properties
Atomic Number
91   
27
67   
99+
Electron Configuration
[Rn] 5f2 6d1 7s2   
[Xe] 4f11 6s2   
Crystal Structure
Tetragonal (TETR)   
Hexagonal Close Packed (HCP)   
Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100   
HCP-Crystal-Structure-of-Holmium.jpg#100   
Atom
  
  
Number of Protons
91   
27
67   
99+
Number of Neutrons
122   
21
98   
34
Number of Electrons
91   
27
67   
99+
Radius of an Atom
  
  
Atomic Radius
163.00 pm   
25
176.00 pm   
18
Covalent Radius
200.00 pm   
11
192.00 pm   
17
Van der Waals Radius
243.00 pm   
11
216.00 pm   
24
Atomic Weight
231.04 amu   
24
164.93 amu   
99+
Atomic Volume
15.00 cm3/mol   
34
18.70 cm3/mol   
24
Adjacent Atomic Numbers
  
  
Previous Element
Thorium
  
Dysprosium
  
Next Element
Uranium
  
Erbium
  
Valence Electron Potential
92.00 (-eV)   
11
47.90 (-eV)   
31
Lattice Constant
392.50 pm   
23
357.73 pm   
38
Lattice Angles
π/2, π/2, π/2   
π/2, π/2, 2 π/3   
Lattice C/A Ratio
Not Available   
1.57   
17
Mechanical Properties
Density
  
  
Density At Room Temperature
15.37 g/cm3   
20
8.79 g/cm3   
99+
Density When Liquid (at m.p.)
Not Available   
8.34 g/cm3   
26
Tensile Strength
Not Available   
Not Available   
Viscosity
Not Available   
Not Available   
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available   
0.00 (Pa)   
16
Elasticity properties
  
  
Shear Modulus
Not Available   
26.30 GPa   
28
Bulk Modulus
Not Available   
40.20 GPa   
32
Young's Modulus
Not Available   
64.80 GPa   
31
Poisson Ratio
Not Available   
0.23   
29
Other Mechanical Properties
Unknown   
Ductile, Malleable, Sectile   
Magnetic Properties
Magnetic Characteristics
  
  
Specific Gravity
15.37   
12
8.80   
35
Magnetic Ordering
Paramagnetic   
Paramagnetic   
Electrical Properties
  
  
Electrical Property
Conductor   
Conductor   
Resistivity
177.00 nΩ·m   
21
814.00 nΩ·m   
4
Electrical Conductivity
0.05 106/cm Ω   
34
0.01 106/cm Ω   
99+
Electron Affinity
Not Available   
50.00 kJ/mol   
21
Thermal Properties
Specific Heat
0.12 J/(kg K)   
40
0.16 J/(kg K)   
35
Molar Heat Capacity
Not Available   
27.15 J/mol·K   
19
Thermal Conductivity
47.00 W/m·K   
32
16.20 W/m·K   
99+
Critical Temperature
Not Available   
Not Available   
Thermal Expansion
9.90 µm/(m·K)   
40
11.20 µm/(m·K)   
35
Enthalpy
  
  
Enthalpy of Vaporization
Not Available   
241.00 kJ/mol   
38
Enthalpy of Fusion
12.34 kJ/mol   
28
11.76 kJ/mol   
29
Enthalpy of Atomization
Not Available   
301.00 kJ/mol   
36
Standard Molar Entropy
198.10 J/mol.K   
1
75.30 J/mol.K   
8
Periodic Table >>
<< All

Compare Actinide Series

Actinide Metals

Actinide Metals

» More Actinide Metals

Compare Actinide Series

» More Compare Actinide Series
Home | About | Contact | Disclaimer | Terms of use
© A softusvista inc. venture!