Symbol
Tb
  
Cm
  
Group Number
Not Available
  
Not Available
  
Period Number
6
  
7
  
Block
f block
  
f block
  
Element Family
Lanthanide
  
Actinide
  
Space Group Name
P63/mmc
  
Not Available
  
Space Group Number
Not Available
  
Interesting Facts
- At times Terbium metal acts same as Calcium.
- Terbium metal closely similar to Lanthanum metal.
  
- Curium metal does not occur free in nature.
- Curium metal is a synthetically produced metal.
  
Sources
Found in Minerals, Found with Other Rare Earth Metals, Mining, Ores of Minerals
  
Bombarding Plutonium with Helium Ions
  
History
  
  
Who Discovered
Carl Gustaf Mosander
  
Glenn T. Seaborg, Ralph A. James, Albert Ghiorso
  
Discovery
In 1842
  
In 1944
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~0.00000001 %
  
29
~-9999 %
  
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Not Available
  
Abundance In Oceans
Not Available
  
Uses & Benefits
- Terbium salts are used in optical devices like laser devices.
-
Terbium’s alloy lengthens and shortens the magnetic field and this effect forms loudspeaker.
  
- Curium metal is used to provide power to electrical equipment for space missions.
  
Industrial Uses
Electronic Industry
  
NA
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys
  
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
Melting Point
1,356.00 °C
  
33
1,340.00 °C
  
34
Boiling Point
3,123.00 °C
  
29
3,110.00 °C
  
30
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Silver
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Brinell Hardness
Not Available
  
Vickers Hardness
Not Available
  
Speed of Sound
2,620.00 m/s
  
35
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 Formula
Tb
  
Cm
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Not Available
  
Allred Rochow Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Not Available
  
Ionization Energies
  
  
1st Energy Level
603.40 kJ/mol
  
99+
581.00 kJ/mol
  
99+
2nd Energy Level
1,174.80 kJ/mol
  
99+
1,196.00 kJ/mol
  
99+
3rd Energy Level
2,417.00 kJ/mol
  
99+
2,026.00 kJ/mol
  
99+
4th Energy Level
4,203.00 kJ/mol
  
31
3,550.00 kJ/mol
  
99+
Electrochemical Equivalent
1.98 g/amp-hr
  
31
3.07 g/amp-hr
  
16
Electron Work Function
Not Available
  
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
  
Ionization, Radioactive Isotopes
  
Electron Configuration
[Xe] 4f9 6s2
  
[Rn] 5f7 6d1 7s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Double Hexagonal Close Packed (DHCP)
  
Crystal Lattice
HCP-Crystal-Structure-of-Terbium.jpg#100
  
DHCP-Crystal-Structure-of-Curium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
158.93 amu
  
99+
Atomic Volume
19.20 cm3/mol
  
22
18.28 cm3/mol
  
26
Adjacent Atomic Numbers
  
  
Valence Electron Potential
46.80 (-eV)
  
33
44.50 (-eV)
  
38
Lattice Constant
Not Available
  
Lattice Angles
π/2, π/2, 2 π/3
  
NA
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
8.23 g/cm3
  
99+
13.51 g/cm3
  
25
Density When Liquid (at m.p.)
13.85 g/cm3
  
10
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile, Malleable
  
Unknown
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Antiferromagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Unknown
  
Electrical Conductivity
0.01 10
6/cm Ω
  
99+
Not Available
  
Electron Affinity
50.00 kJ/mol
  
21
Not Available
  
Specific Heat
0.18 J/(kg K)
  
33
Not Available
  
Molar Heat Capacity
28.91 J/mol·K
  
9
Not Available
  
Thermal Conductivity
11.10 W/m·K
  
99+
Not Available
  
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
10.30 µm/(m·K)
  
38
Not Available
  
Enthalpy
  
  
Enthalpy of Vaporization
330.90 kJ/mol
  
26
Not Available
  
Enthalpy of Fusion
10.80 kJ/mol
  
34
15.00 kJ/mol
  
21
Enthalpy of Atomization
314.00 kJ/mol
  
33
Not Available
  
Standard Molar Entropy
73.20 J/mol.K
  
10
Not Available