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Terbium vs Francium


Francium vs Terbium


Periodic Table

Symbol
Tb   
Fr   

Group Number
Not Available   
1   
17

Period Number
6   
7   

Block
f block   
s block   

Element Family
Lanthanide   
Alkali   

CAS Number
7440279   
99+
7440735   
18

Space Group Name
P63/mmc   
Not Available   

Space Group Number
194.00   
5
Not Available   

Facts

Interesting Facts
  • At times Terbium metal acts same as Calcium.
  • Terbium metal closely similar to Lanthanum metal.
  
  • 223 Francium has the longest half life at 21.8.
  • Francium metal is produced by alpha decay in 227Actinium 227.
  

Sources
Found in Minerals, Found with Other Rare Earth Metals, Mining, Ores of Minerals   
Formed by Decay Process, Mining   

History
  
  

Who Discovered
Carl Gustaf Mosander   
Marguerite Perey   

Discovery
In 1842   
In 1939   

Abundance
  
  

Abundance In Universe
5 * 10-8 %   
27
Not Available   

Abundance In Sun
~0.00000001 %   
29
~-9999 %   

Abundance In Meteorites
0.00 %   
99+
Not Available   

Abundance In Earth's Crust
0.00 %   
40
Not Available   

Abundance In Oceans
0.00 %   
99+
Not Available   

Uses

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.
  
  • Francium has no known uses as it has a half life of only 22 minutes.
  

Industrial Uses
Electronic Industry   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys   
NA   

Biological Properties
  
  

Toxicity
Low Toxic   
NA   

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
1,356.00 °C   
33
27.00 °C   
99+

Boiling Point
3,123.00 °C   
29
677.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
NA   

Luster
Metallic   
NA   

Hardness
  
  

Brinell Hardness
677.00 MPa   
17
Not Available   

Vickers Hardness
863.00 MPa   
13
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 Properties

Chemical Formula
Tb   
Fr   

Isotopes
  
  

Known Isotopes
26   
13
33   
6

Electronegativity
  
  

Pauling Electronegativity
Not Available   
0.70   
99+

Allred Rochow Electronegativity
1.10   
30
0.86   
99+

Mulliken-Jaffe Electronegativity
Not Available   
0.68   
25

Allen Electronegativity
Not Available   
0.67   
99+

Electropositivity
  
  

Pauling Electropositivity
Not Available   
3.30   
1

Ionization Energies
  
  

1st Energy Level
603.40 kJ/mol   
99+
380.00 kJ/mol   
99+

2nd Energy Level
1,174.80 kJ/mol   
99+
Not Available   

3rd Energy Level
2,417.00 kJ/mol   
99+
Not Available   

4th Energy Level
4,203.00 kJ/mol   
31
Not Available   

Electrochemical Equivalent
1.98 g/amp-hr   
31
8.32 g/amp-hr   
1

Electron Work Function
3.00 eV   
36
Not Available   

Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility   
Ionization, Radioactive Isotopes, Radioactivity, Solubility   

Atomic Properties

Atomic Number
65   
99+
87   
31

Electron Configuration
[Xe] 4f9 6s2   
[Rn] 7s1   

Crystal Structure
Hexagonal Close Packed (HCP)   
Body Centered Cubic (BCC)   

Crystal Lattice
HCP-Crystal-Structure-of-Terbium.jpg#100   
BCC-Crystal-Structure-.jpg#100   

Atom
  
  

Number of Protons
65   
99+
87   
31

Number of Neutrons
94   
36
136   
17

Number of Electrons
65   
99+
87   
31

Radius of an Atom
  
  

Atomic Radius
177.00 pm   
17
Not Available   

Covalent Radius
194.00 pm   
16
260.00 pm   
1

Van der Waals Radius
221.00 pm   
22
348.00 pm   
1

Atomic Weight
158.93 amu   
99+
223.00 amu   
27

Atomic Volume
19.20 cm3/mol   
22
Not Available   

Adjacent Atomic Numbers
  
  

Previous Element
Gadolinium
  
Polonium
  

Next Element
Dysprosium
  
Radium
  

Valence Electron Potential
46.80 (-eV)   
33
8.00 (-eV)   
99+

Lattice Constant
360.10 pm   
36
Not Available   

Lattice Angles
π/2, π/2, 2 π/3   
NA   

Lattice C/A Ratio
1.58   
13
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
8.23 g/cm3   
99+
1.87 g/cm3   
99+

Density When Liquid (at m.p.)
7.65 g/cm3   
30
Not Available   

Tensile Strength
60.00 MPa   
17
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)   
29
Not Available   

Vapor Pressure at 2000 K
12.50 (Pa)   
8
Not Available   

Elasticity properties
  
  

Shear Modulus
22.10 GPa   
32
Not Available   

Bulk Modulus
38.70 GPa   
33
Not Available   

Young's Modulus
55.70 GPa   
34
Not Available   

Poisson Ratio
0.26   
21
Not Available   

Other Mechanical Properties
Ductile, Malleable   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
8.23   
39
Not Available   

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Poor Conductor   

Resistivity
1.15 nΩ·m   
99+
3.00 nΩ·m   
99+

Electrical Conductivity
0.01 106/cm Ω   
99+
0.03 106/cm Ω   
40

Electron Affinity
50.00 kJ/mol   
21
Not Available   

Thermal Properties

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+
15.00 W/m·K   
99+

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
Not Available   

Enthalpy of Atomization
314.00 kJ/mol   
33
71.00 kJ/mol   
99+

Standard Molar Entropy
73.20 J/mol.K   
10
Not Available   

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