Holmium vs Curium
Periodic Table
Symbol
Ho
Cm
Group Number
Not Available
Not Available
Period Number
6
7
Block
f block
f block
Element Family
Lanthanide
Actinide
CAS Number
7440600
29
7440519
36
Space Group Name
P63/mmc
Not Available
Space Group Number
194.00
5
Not Available
Facts
Interesting Facts
- Holmium metal is very soft and malleable.
- Holmium metal is well known for its corrosion resistivity.
- Curium metal does not occur free in nature.
- Curium metal is a synthetically produced metal.
Sources
Found in Minerals, Mining, Ores of Minerals
Bombarding Plutonium with Helium Ions
History
Who Discovered
Marc Delafontaine
Glenn T. Seaborg, Ralph A. James, Albert Ghiorso
Discovery
In 1878
In 1944
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
Not Available
Abundance In Oceans
0.00 %
99+
Not Available
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.
- Curium metal is used to provide power to electrical equipment for space missions.
Industrial Uses
NA
NA
Medical Uses
NA
NA
Other Uses
Alloys, Nuclear Research
Research Purposes
Biological Properties
Toxicity
Low Toxic
Unknown
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
1,340.00 °C
34
Boiling Point
2,600.00 °C
99+
3,110.00 °C
30
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
Cm
Isotopes
Known Isotopes
34
5
15
24
Electronegativity
Pauling Electronegativity
1.23
37
1.30
32
Allred Rochow Electronegativity
1.10
30
1.20
27
Electropositivity
Pauling Electropositivity
2.77
17
2.70
22
Ionization Energies
1st Energy Level
581.00 kJ/mol
99+
581.00 kJ/mol
99+
2nd Energy Level
1,140.00 kJ/mol
99+
1,196.00 kJ/mol
99+
3rd Energy Level
2,204.00 kJ/mol
99+
2,026.00 kJ/mol
99+
4th Energy Level
4,100.00 kJ/mol
34
3,550.00 kJ/mol
99+
Electrochemical Equivalent
2.02 g/amp-hr
29
3.07 g/amp-hr
16
Electron Work Function
Not Available
Not Available
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Ionization, Radioactive Isotopes
Atomic Properties
Atomic Number
67
99+
96
22
Electron Configuration
[Xe] 4f11 6s2
[Rn] 5f7 6d1 7s2
Crystal Structure
Hexagonal Close Packed (HCP)
Double Hexagonal Close Packed (DHCP)
Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100
DHCP-Crystal-Structure-of-Curium.jpg#100
Atom
Number of Protons
67
99+
96
22
Number of Neutrons
98
34
151
10
Number of Electrons
67
99+
96
22
Radius of an Atom
Atomic Radius
176.00 pm
18
174.00 pm
20
Covalent Radius
192.00 pm
17
169.00 pm
26
Van der Waals Radius
216.00 pm
24
200.00 pm
28
Atomic Weight
164.93 amu
99+
247.00 amu
18
Atomic Volume
18.70 cm3/mol
24
18.28 cm3/mol
26
Adjacent Atomic Numbers
Valence Electron Potential
47.90 (-eV)
31
44.50 (-eV)
38
Lattice Constant
357.73 pm
38
Not Available
Lattice Angles
π/2, π/2, 2 π/3
NA
Lattice C/A Ratio
1.57
17
Not Available
Mechanical Properties
Density
Density At Room Temperature
8.79 g/cm3
99+
13.51 g/cm3
25
Density When Liquid (at m.p.)
8.34 g/cm3
26
13.85 g/cm3
10
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
13.51
17
Magnetic Ordering
Paramagnetic
Antiferromagnetic
Electrical Properties
Electrical Property
Conductor
Unknown
Resistivity
814.00 nΩ·m
4
1.25 nΩ·m
99+
Electrical Conductivity
0.01 106/cm Ω
99+
Not Available
Electron Affinity
50.00 kJ/mol
21
Not Available
Thermal Properties
Specific Heat
0.16 J/(kg K)
35
Not Available
Molar Heat Capacity
27.15 J/mol·K
19
Not Available
Thermal Conductivity
16.20 W/m·K
99+
Not Available
Critical Temperature
Not Available
Not Available
Thermal Expansion
11.20 µm/(m·K)
35
Not Available
Enthalpy
Enthalpy of Vaporization
241.00 kJ/mol
38
Not Available
Enthalpy of Fusion
11.76 kJ/mol
29
15.00 kJ/mol
21
Enthalpy of Atomization
301.00 kJ/mol
36
Not Available
Standard Molar Entropy
75.30 J/mol.K
8
Not Available
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