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Holmium vs Actinium

Holmium
Actinium
Actinium vs Holmium


Periodic Table
Symbol
Ho  
Ac  
Group Number
3  
15
3  
15
Period Number
6  
7  
Block
f block  
f block  
Element Family
Lanthanide  
Actinide  
CAS Number
7440600  
29
7440348  
99+
Space Group Name
P63/mmc  
Fm_ 3m  
Space Group Number
194.00  
7
225.00  
3
Facts
Interesting Facts
  • Holmium metal is very soft and malleable.
  • Holmium metal is well known for its corrosion resistivity.
  
Actinium glows in the dark due to its radioactivity.  
Sources
Found in Minerals, Mining, Ores of Minerals  
Obtained by Treating Radium with Neutrons, Ores of metals  
History
  
  
Who Discovered
Marc Delafontaine  
Friedrich Oskar Giesel  
Discovery
In 1878  
In 1902  
Abundance
  
  
Abundance In Universe
0.00 %  
28
0.00 %  
34
Abundance In Sun
-  
0.00 %  
26
Abundance In Meteorites
0.00 %  
99+
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.
  
  • Actinium metal has a great source of alpha rays but it is hardly used outside research purpose.
  
Industrial Uses
-  
-  
Medical Uses
-  
-  
Other Uses
Alloys, Nuclear Research  
Alloys, Nuclear Research, Research Purposes  
Biological Properties
  
  
Toxicity
Low Toxic  
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
1,227.00 °C  
38
Boiling Point
2,600.00 °C  
99+
3,200.00 °C  
27
Appearance
  
  
Physical State
Solid  
Solid  
Color
Silvery White  
Silvery White  
Luster
Metallic  
-  
Hardness
  
  
Mohs Hardness
4.00  
11
6.50  
5
Brinell Hardness
746.00 MPa  
14
70.00 MPa  
99+
Vickers Hardness
481.00 MPa  
36
260.00 MPa  
99+
Speed of Sound
2,760.00 m/s  
99+
3,430.00 m/s  
32
Optical Properties
  
  
Refractive Index
1.67  
29
1.00  
99+
Reflectivity
67.00 %  
16
62.00 %  
21
Allotropes
No  
No  
α Allotropes
-  
-  
β Allotropes
-  
-  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Ho  
Ac  
Isotopes
  
  
Known Isotopes
34  
5
29  
10
Electronegativity
  
  
Pauling Electronegativity
1.23  
38
1.10  
99+
Sanderson Electronegativity
1.23  
30
1.10  
38
Allred Rochow Electronegativity
1.10  
31
1.00  
37
Mulliken-Jaffe Electronegativity
1.23  
37
1.10  
99+
Allen Electronegativity
1.23  
99+
1.10  
99+
Electropositivity
  
  
Pauling Electropositivity
2.77  
17
2.90  
10
Ionization Energies
  
  
1st Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
2nd Energy Level
1,140.00 kJ/mol  
99+
1,170.00 kJ/mol  
99+
3rd Energy Level
2,204.00 kJ/mol  
99+
1,900.00 kJ/mol  
99+
4th Energy Level
4,100.00 kJ/mol  
99+
4,700.00 kJ/mol  
33
5th Energy Level
5,810.00 kJ/mol  
99+
4,990.00 kJ/mol  
99+
6th Energy Level
5,810.00 kJ/mol  
99+
5,750.00 kJ/mol  
99+
7th Energy level
5,810.00 kJ/mol  
99+
5,750.00 kJ/mol  
99+
8th Energy Level
5,810.00 kJ/mol  
99+
5,750.00 kJ/mol  
99+
9th Energy Level
6,500.00 kJ/mol  
39
4,990.00 kJ/mol  
99+
10th Energy Level
6,500.00 kJ/mol  
99+
4,990.00 kJ/mol  
99+
11th Energy Level
5,810.00 kJ/mol  
99+
4,990.00 kJ/mol  
99+
12th Energy Level
5,810.00 kJ/mol  
99+
49,900.00 kJ/mol  
21
13th Energy Level
5,810.00 kJ/mol  
99+
4,990.00 kJ/mol  
99+
14th Energy Level
5,810.00 kJ/mol  
40
4,990.00 kJ/mol  
99+
15th Energy Level
58,100.00 kJ/mol  
99+
49,900.00 kJ/mol  
99+
16th Energy Level
581.00 kJ/mol  
99+
49,900.00 kJ/mol  
99+
17th Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
18th Energy Level
5,810.00 kJ/mol  
99+
4,990.00 kJ/mol  
99+
19th Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
20th Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
21st Energy Level
581.00 kJ/mol  
99+
4,990.00 kJ/mol  
25
22nd Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
23rd Energy Level
5,810.00 kJ/mol  
20
4,990.00 kJ/mol  
29
24th Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
25th Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
26th Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
27th Energy Level
584.70 kJ/mol  
99+
499.00 kJ/mol  
99+
28th Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
29th Energy Level
584.70 kJ/mol  
99+
499.00 kJ/mol  
99+
30th Energy Level
581.00 kJ/mol  
99+
499.00 kJ/mol  
99+
Electrochemical Equivalent
2.02 g/amp-hr  
33
2.82 g/amp-hr  
22
Electron Work Function
4.90 eV  
12
4.38 eV  
23
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility  
Ionization, Radioactive Isotopes, Radioactivity, Solubility  
Atomic
Atomic Number
67  
99+
89  
29
Electron Configuration
[Xe] 4f11 6s2  
[Rn] 6d1 7s2  
Crystal Structure
Hexagonal Close Packed (HCP)  
Face Centered Cubic (FCC)  
Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100  
FCC-Crystal-Structure-of-Actinium.jpg#100  
Atom
  
  
Number of Protons
67  
99+
89  
29
Number of Neutrons
98  
35
138  
17
Number of Electrons
67  
99+
89  
29
Radius of an Atom
  
  
Atomic Radius
176.00 pm  
20
195.00 pm  
9
Covalent Radius
192.00 pm  
17
186.00 pm  
21
Van der Waals Radius
216.00 pm  
30
215.00 pm  
31
Atomic Weight
164.93 amu  
99+
227.00 amu  
25
Atomic Volume
18.70 cm3/mol  
36
22.54 cm3/mol  
20
Adjacent Atomic Numbers
  
  
Previous Element
Dysprosium
  
Radium
  
Next Element
Erbium
  
Thorium
  
Valence Electron Potential
47.90 (-eV)  
32
38.60 (-eV)  
99+
Lattice Constant
357.73 pm  
99+
567.00 pm  
9
Lattice Angles
π/2, π/2, 2 π/3  
π/2, π/2, π/2  
Lattice C/A Ratio
1.57  
40
1.89  
2
Mechanical
Density
  
  
Density At Room Temperature
8.79 g/cm3  
99+
10.00 g/cm3  
40
Density When Liquid (at m.p.)
8.34 g/cm3  
99+
10.07 g/cm3  
40
Tensile Strength
270.00 MPa  
17
65.00 MPa  
33
Viscosity
0.00  
25
0.00  
25
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
17
0.00 (Pa)  
22
Vapor Pressure at 2000 K
0.00 (Pa)  
30
0.00 (Pa)  
30
Elasticity properties
  
  
Shear Modulus
26.30 GPa  
35
25.00 GPa  
38
Bulk Modulus
40.20 GPa  
37
94.00 GPa  
17
Young's Modulus
64.80 GPa  
33
130.00 GPa  
16
Poisson Ratio
0.23  
29
0.34  
10
Other Mechanical Properties
Ductile, Malleable, Sectile  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
8.80  
99+
10.07  
99+
Magnetic Ordering
Paramagnetic  
Paramagnetic  
Permeability
0.00 H/m  
7
0.00 H/m  
17
Susceptibility
0.00  
11
0.00  
24
Electrical Properties
  
  
Electrical Property
Conductor  
-  
Resistivity
814.00 nΩ·m  
4
5.20 nΩ·m  
99+
Electrical Conductivity
0.01 106/cm Ω  
99+
0.15 106/cm Ω  
13
Electron Affinity
50.00 kJ/mol  
26
33.20 kJ/mol  
34
Thermal
Specific Heat
0.16 J/(kg K)  
36
0.12 J/(kg K)  
99+
Molar Heat Capacity
27.15 J/mol·K  
25
27.20 J/mol·K  
24
Thermal Conductivity
16.20 W/m·K  
99+
12.00 W/m·K  
99+
Critical Temperature
1,747.00 K  
34
1,323.00 K  
99+
Thermal Expansion
11.20 µm/(m·K)  
99+
12.10 µm/(m·K)  
99+
Enthalpy
  
  
Enthalpy of Vaporization
241.00 kJ/mol  
99+
120.00 kJ/mol  
99+
Enthalpy of Fusion
11.76 kJ/mol  
35
14.20 kJ/mol  
28
Enthalpy of Atomization
301.00 kJ/mol  
99+
301.00 kJ/mol  
99+
Standard Molar Entropy
75.30 J/mol.K  
8
56.50 J/mol.K  
33
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