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Holmium vs Polonium

Holmium
Polonium
Polonium vs Holmium


Periodic Table
Symbol
Ho  
Po  
Group Number
3  
15
16  
2
Period Number
6  
6  
Block
f block  
p block  
Element Family
Lanthanide  
Post-​Transition  
CAS Number
7440600  
29
7440086  
99+
Space Group Name
P63/mmc  
Pm-3m  
Space Group Number
194.00  
7
221.00  
4
Facts
Interesting Facts
  • Holmium metal is very soft and malleable.
  • Holmium metal is well known for its corrosion resistivity.
  
  • Polonium was the first radioactive element to be discovered.
  • Polonium element and its compounds are highly radioactive.
  • Its alloy with Beryllium provides source of neutrons.
  
Sources
Found in Minerals, Mining, Ores of Minerals  
Mining, Ores of metals  
History
  
  
Who Discovered
Marc Delafontaine  
Pierre Curie and Marie Curie  
Discovery
In 1878  
In 1898  
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+
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.
  
  • Polonium metal has different Allotropes, it is used in antistatic devices and for research purpose.
  • A 1 gram of Polonium can reach a temperature of 500°C, hence it is used as a heat source for space equipment.
  
Industrial Uses
-  
Aerospace Industry, Ammunition Industry  
Medical Uses
-  
-  
Other Uses
Alloys, Nuclear Research  
Alloys  
Biological Properties
  
  
Toxicity
Low Toxic  
Highly 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
254.00 °C  
99+
Boiling Point
2,600.00 °C  
99+
962.00 °C  
99+
Appearance
  
  
Physical State
Solid  
Solid  
Color
Silvery White  
Silver  
Luster
Metallic  
-  
Hardness
  
  
Mohs Hardness
4.00  
11
2.50  
15
Brinell Hardness
746.00 MPa  
14
70.00 MPa  
99+
Vickers Hardness
481.00 MPa  
36
30.00 MPa  
99+
Speed of Sound
2,760.00 m/s  
99+
2,260.00 m/s  
99+
Optical Properties
  
  
Refractive Index
1.67  
29
2.70  
3
Reflectivity
67.00 %  
16
50.00 %  
31
Allotropes
No  
Yes  
α Allotropes
-  
α-polonium  
β Allotropes
-  
β-polonium  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Ho  
Po  
Isotopes
  
  
Known Isotopes
34  
5
29  
10
Electronegativity
  
  
Pauling Electronegativity
1.23  
38
2.00  
8
Sanderson Electronegativity
1.23  
30
2.00  
10
Allred Rochow Electronegativity
1.10  
31
1.76  
3
Mulliken-Jaffe Electronegativity
1.23  
37
2.48  
1
Allen Electronegativity
1.23  
99+
2.19  
2
Electropositivity
  
  
Pauling Electropositivity
2.77  
17
2.00  
99+
Ionization Energies
  
  
1st Energy Level
581.00 kJ/mol  
99+
812.10 kJ/mol  
14
2nd Energy Level
1,140.00 kJ/mol  
99+
1,833.20 kJ/mol  
17
3rd Energy Level
2,204.00 kJ/mol  
99+
812.10 kJ/mol  
99+
4th Energy Level
4,100.00 kJ/mol  
99+
8,121.00 kJ/mol  
7
5th Energy Level
5,810.00 kJ/mol  
99+
8,120.00 kJ/mol  
12
6th Energy Level
5,810.00 kJ/mol  
99+
8,120.00 kJ/mol  
32
7th Energy level
5,810.00 kJ/mol  
99+
8,120.00 kJ/mol  
26
8th Energy Level
5,810.00 kJ/mol  
99+
8,120.00 kJ/mol  
26
9th Energy Level
6,500.00 kJ/mol  
39
8,120.00 kJ/mol  
23
10th Energy Level
6,500.00 kJ/mol  
99+
8,120.00 kJ/mol  
27
11th Energy Level
5,810.00 kJ/mol  
99+
8,120.00 kJ/mol  
26
12th Energy Level
5,810.00 kJ/mol  
99+
8,120.00 kJ/mol  
99+
13th Energy Level
5,810.00 kJ/mol  
99+
8,120.00 kJ/mol  
19
14th Energy Level
5,810.00 kJ/mol  
40
8,120.00 kJ/mol  
18
15th Energy Level
58,100.00 kJ/mol  
99+
81,200.00 kJ/mol  
15
16th Energy Level
581.00 kJ/mol  
99+
81,200.00 kJ/mol  
12
17th Energy Level
581.00 kJ/mol  
99+
812.10 kJ/mol  
32
18th Energy Level
5,810.00 kJ/mol  
99+
8,120.00 kJ/mol  
21
19th Energy Level
581.00 kJ/mol  
99+
812.10 kJ/mol  
29
20th Energy Level
581.00 kJ/mol  
99+
812.00 kJ/mol  
22
21st Energy Level
581.00 kJ/mol  
99+
812.10 kJ/mol  
40
22nd Energy Level
581.00 kJ/mol  
99+
812.00 kJ/mol  
17
23rd Energy Level
5,810.00 kJ/mol  
20
812.10 kJ/mol  
99+
24th Energy Level
581.00 kJ/mol  
99+
812.10 kJ/mol  
13
25th Energy Level
581.00 kJ/mol  
99+
812.10 kJ/mol  
11
26th Energy Level
581.00 kJ/mol  
99+
812.10 kJ/mol  
11
27th Energy Level
584.70 kJ/mol  
99+
812.10 kJ/mol  
10
28th Energy Level
581.00 kJ/mol  
99+
812.10 kJ/mol  
16
29th Energy Level
584.70 kJ/mol  
99+
812.10 kJ/mol  
15
30th Energy Level
581.00 kJ/mol  
99+
812.00 kJ/mol  
11
Electrochemical Equivalent
2.02 g/amp-hr  
33
3.90 g/amp-hr  
8
Electron Work Function
4.90 eV  
12
4.50 eV  
19
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility  
Ionization, Radioactive Isotopes, Solubility  
Atomic
Atomic Number
67  
99+
84  
32
Electron Configuration
[Xe] 4f11 6s2  
[Xe] 4f14 5d10 6s2 6p4  
Crystal Structure
Hexagonal Close Packed (HCP)  
Monoclinic (MON)  
Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100  
MON-Crystal-Structure-of-Polonium.jpg#100  
Atom
  
  
Number of Protons
67  
99+
84  
32
Number of Neutrons
98  
35
125  
20
Number of Electrons
67  
99+
84  
32
Radius of an Atom
  
  
Atomic Radius
176.00 pm  
20
168.00 pm  
25
Covalent Radius
192.00 pm  
17
140.00 pm  
99+
Van der Waals Radius
216.00 pm  
30
197.00 pm  
36
Atomic Weight
164.93 amu  
99+
209.00 amu  
28
Atomic Volume
18.70 cm3/mol  
36
22.23 cm3/mol  
22
Adjacent Atomic Numbers
  
  
Previous Element
Dysprosium
  
Bismuth
  
Next Element
Erbium
  
Francium
  
Valence Electron Potential
47.90 (-eV)  
32
9.30 (-eV)  
99+
Lattice Constant
357.73 pm  
99+
335.90 pm  
99+
Lattice Angles
π/2, π/2, 2 π/3  
π/2, π/2, π/2  
Lattice C/A Ratio
1.57  
40
1.46  
99+
Mechanical
Density
  
  
Density At Room Temperature
8.79 g/cm3  
99+
9.20 g/cm3  
99+
Density When Liquid (at m.p.)
8.34 g/cm3  
99+
9.40 g/cm3  
99+
Tensile Strength
270.00 MPa  
17
50.00 MPa  
38
Viscosity
0.00  
25
0.00  
26
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)  
37
Elasticity properties
  
  
Shear Modulus
26.30 GPa  
35
24.00 GPa  
40
Bulk Modulus
40.20 GPa  
37
46.00 GPa  
28
Young's Modulus
64.80 GPa  
33
46.00 GPa  
99+
Poisson Ratio
0.23  
29
0.23  
30
Other Mechanical Properties
Ductile, Malleable, Sectile  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
8.80  
99+
9.32  
99+
Magnetic Ordering
Paramagnetic  
Nonmagnetic  
Permeability
0.00 H/m  
7
0.00 H/m  
15
Susceptibility
0.00  
11
0.00  
24
Electrical Properties
  
  
Electrical Property
Conductor  
Conductor  
Resistivity
814.00 nΩ·m  
4
0.40 nΩ·m  
99+
Electrical Conductivity
0.01 106/cm Ω  
99+
0.02 106/cm Ω  
99+
Electron Affinity
50.00 kJ/mol  
26
183.30 kJ/mol  
3
Thermal
Specific Heat
0.16 J/(kg K)  
36
0.12 J/(kg K)  
99+
Molar Heat Capacity
27.15 J/mol·K  
25
26.40 J/mol·K  
36
Thermal Conductivity
16.20 W/m·K  
99+
20.00 W/m·K  
99+
Critical Temperature
1,747.00 K  
34
527.00 K  
99+
Thermal Expansion
11.20 µm/(m·K)  
99+
23.50 µm/(m·K)  
16
Enthalpy
  
  
Enthalpy of Vaporization
241.00 kJ/mol  
99+
60.30 kJ/mol  
99+
Enthalpy of Fusion
11.76 kJ/mol  
35
13.00 kJ/mol  
32
Enthalpy of Atomization
301.00 kJ/mol  
99+
134.00 kJ/mol  
99+
Standard Molar Entropy
75.30 J/mol.K  
8
41.10 J/mol.K  
99+
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