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Holmium vs Promethium


Promethium vs Holmium


Periodic Table

Symbol
Ho  
Pm  

Group Number
3  
15
3  
15

Period Number
6  
6  

Block
f block  
f block  

Element Family
Lanthanide  
Lanthanide  

CAS Number
7440600  
29
7440122  
99+

Space Group Name
P63/mmc  
-  

Space Group Number
194.00  
7
194.00  
7

Facts

Interesting Facts
  • Holmium metal is very soft and malleable.
  • Holmium metal is well known for its corrosion resistivity.
  
  • Promethium metal found in Pitchblende.
  • Promethium metal is highly radioactive metal.
  

Sources
Found in Minerals, Mining, Ores of Minerals  
Found in Minerals, Mining  

History
  
  

Who Discovered
Marc Delafontaine  
Chien Shiung Wu, Emilio Segrè, Hans Bethe  

Discovery
In 1878  
In 1942  

Abundance
  
  

Abundance In Universe
0.00 %  
28
0.00 %  
40

Abundance In Sun
-  
-  

Abundance In Meteorites
0.00 %  
99+
-  

Abundance In Earth's Crust
0.00 %  
38
0.00 %  
99+

Abundance In Oceans
0.00 %  
99+
-  

Abundance In Humans
0.00 %  
24
0.00 %  
24

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.
  
  • It is used for research purpose. Very small amount of this metal is used in atomic batteries.
  • Its radioactive decay is used for a phosphor to give off light. The light emitted is converted into electricity.
  

Industrial Uses
-  
-  

Medical Uses
-  
-  

Other Uses
Alloys, Nuclear Research  
-  

Biological Properties
  
  

Toxicity
Low Toxic  
Non Toxic  

Present in Human Body
No  
No  

In Blood
0.00 Blood/mg dm-3  
40
0.00 Blood/mg dm-3  
40

In Bone
0.00 p.p.m.  
99+
0.00 p.p.m.  
99+

Physical

Melting Point
1,461.00 °C  
30
1,042.00 °C  
99+

Boiling Point
2,600.00 °C  
99+
3,000.00 °C  
32

Appearance
  
  

Physical State
Solid  
Solid  

Color
Silvery White  
-  

Luster
Metallic  
Metallic  

Hardness
  
  

Mohs Hardness
4.00  
11
-  

Brinell Hardness
746.00 MPa  
14
400.00 MPa  
34

Vickers Hardness
481.00 MPa  
36
600.00 MPa  
28

Speed of Sound
2,760.00 m/s  
99+
2,260.00 m/s  
99+

Optical Properties
  
  

Refractive Index
1.67  
29
1.70  
27

Reflectivity
67.00 %  
16
63.00 %  
20

Allotropes
No  
No  

α Allotropes
-  
-  

β Allotropes
-  
-  

γ Allotropes
-  
-  

Chemical

Chemical Formula
Ho  
Pm  

Isotopes
  
  

Known Isotopes
34  
5
27  
12

Electronegativity
  
  

Pauling Electronegativity
1.23  
38
1.13  
99+

Sanderson Electronegativity
1.23  
30
1.13  
36

Allred Rochow Electronegativity
1.10  
31
1.07  
33

Mulliken-Jaffe Electronegativity
1.23  
37
1.13  
99+

Allen Electronegativity
1.23  
99+
1.13  
99+

Electropositivity
  
  

Pauling Electropositivity
2.77  
17
2.20  
39

Ionization Energies
  
  

1st Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

2nd Energy Level
1,140.00 kJ/mol  
99+
1,050.00 kJ/mol  
99+

3rd Energy Level
2,204.00 kJ/mol  
99+
2,150.00 kJ/mol  
99+

4th Energy Level
4,100.00 kJ/mol  
99+
3,970.00 kJ/mol  
99+

5th Energy Level
5,810.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

6th Energy Level
5,810.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

7th Energy level
5,810.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

8th Energy Level
5,810.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

9th Energy Level
6,500.00 kJ/mol  
39
5,400.00 kJ/mol  
99+

10th Energy Level
6,500.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

11th Energy Level
5,810.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

12th Energy Level
5,810.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

13th Energy Level
5,810.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

14th Energy Level
5,810.00 kJ/mol  
40
5,400.00 kJ/mol  
99+

15th Energy Level
58,100.00 kJ/mol  
99+
54,000.00 kJ/mol  
99+

16th Energy Level
581.00 kJ/mol  
99+
54,000.00 kJ/mol  
99+

17th Energy Level
581.00 kJ/mol  
99+
540.50 kJ/mol  
99+

18th Energy Level
5,810.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

19th Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

20th Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

21st Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

22nd Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

23rd Energy Level
5,810.00 kJ/mol  
20
540.00 kJ/mol  
99+

24th Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

25th Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

26th Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

27th Energy Level
584.70 kJ/mol  
99+
540.00 kJ/mol  
99+

28th Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

29th Energy Level
584.70 kJ/mol  
99+
540.00 kJ/mol  
99+

30th Energy Level
581.00 kJ/mol  
99+
540.00 kJ/mol  
99+

Electrochemical Equivalent
2.02 g/amp-hr  
33
1.80 g/amp-hr  
40

Electron Work Function
4.90 eV  
12
5.30 eV  
5

Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility  
Ionization, Radioactive Isotopes, Solubility  

Atomic

Atomic Number
67  
99+
61  
99+

Electron Configuration
[Xe] 4f11 6s2  
[Xe] 4f5 6s2  

Crystal Structure
Hexagonal Close Packed (HCP)  
Double Hexagonal Close Packed (DHCP)  

Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100  
DHCP-Crystal-Structure-of-Promethium.jpg#100  

Atom
  
  

Number of Protons
67  
99+
61  
99+

Number of Neutrons
98  
35
84  
99+

Number of Electrons
67  
99+
61  
99+

Radius of an Atom
  
  

Atomic Radius
176.00 pm  
20
183.00 pm  
12

Covalent Radius
192.00 pm  
17
199.00 pm  
12

Van der Waals Radius
216.00 pm  
30
236.00 pm  
20

Atomic Weight
164.93 amu  
99+
145.00 amu  
99+

Atomic Volume
18.70 cm3/mol  
36
22.39 cm3/mol  
21

Adjacent Atomic Numbers
  
  

Previous Element
Neodymium
  

Next Element
Erbium
  
Samarium
  

Valence Electron Potential
47.90 (-eV)  
32
44.10 (-eV)  
40

Lattice Constant
357.73 pm  
99+
-  

Lattice Angles
π/2, π/2, 2 π/3  
-  

Lattice C/A Ratio
1.57  
40
1.63  
14

Mechanical

Density
  
  

Density At Room Temperature
8.79 g/cm3  
99+
7.26 g/cm3  
99+

Density When Liquid (at m.p.)
8.34 g/cm3  
99+
7.26 g/cm3  
99+

Tensile Strength
270.00 MPa  
17
75.00 MPa  
30

Viscosity
0.00  
25
0.00  
25

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)  
17
0.00 (Pa)  
37

Vapor Pressure at 2000 K
0.00 (Pa)  
30
0.00 (Pa)  
31

Elasticity properties
  
  

Shear Modulus
26.30 GPa  
35
18.00 GPa  
99+

Bulk Modulus
40.20 GPa  
37
33.00 GPa  
99+

Young's Modulus
64.80 GPa  
33
46.00 GPa  
99+

Poisson Ratio
0.23  
29
0.28  
17

Other Mechanical Properties
Ductile, Malleable, Sectile  
-  

Magnetic

Magnetic Characteristics
  
  

Specific Gravity
8.80  
99+
7.26  
99+

Magnetic Ordering
Paramagnetic  
Paramagnetic  

Permeability
0.00 H/m  
7
0.00 H/m  
11

Susceptibility
0.00  
11
0.00  
25

Electrical Properties
  
  

Electrical Property
Conductor  
Conductor  

Resistivity
814.00 nΩ·m  
4
0.75 nΩ·m  
99+

Electrical Conductivity
0.01 106/cm Ω  
99+
0.00 106/cm Ω  
99+

Electron Affinity
50.00 kJ/mol  
26
50.00 kJ/mol  
26

Thermal

Specific Heat
0.16 J/(kg K)  
36
0.18 J/(kg K)  
34

Molar Heat Capacity
27.15 J/mol·K  
25
27.60 J/mol·K  
20

Thermal Conductivity
16.20 W/m·K  
99+
17.90 W/m·K  
99+

Critical Temperature
1,747.00 K  
34
1,315.00 K  
99+

Thermal Expansion
11.20 µm/(m·K)  
99+
9.00 µm/(m·K)  
99+

Enthalpy
  
  

Enthalpy of Vaporization
241.00 kJ/mol  
99+
289.00 kJ/mol  
99+

Enthalpy of Fusion
11.76 kJ/mol  
35
7.50 kJ/mol  
99+

Enthalpy of Atomization
301.00 kJ/mol  
99+
310.00 kJ/mol  
99+

Standard Molar Entropy
75.30 J/mol.K  
8
57.00 J/mol.K  
30

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