Samarium vs Francium
Periodic Table
Symbol
Sm
Fr
Group Number
Not Available
1
17
Period Number
6
7
Block
f block
s block
Element Family
Lanthanide
Alkali
CAS Number
7440199
99+
7440735
18
Space Group Name
R_ 3m
Not Available
Space Group Number
166.00
6
Not Available
Facts
Interesting Facts
- Samarium metals helps stimulating body metabolism.
- Samarium metals was 1st observed by Jean Charles Galissard de Marignac in Dydimia in 1853.
- 223 Francium has the longest half life at 21.8.
- Francium metal is produced by alpha decay in 227Actinium 227.
Sources
Found in Minerals, Mining, Ores of Minerals
Formed by Decay Process, Mining
History
Who Discovered
Lecoq de Boisbaudran
Marguerite Perey
Discovery
In 1879
In 1939
Abundance
Abundance In Universe
5 * 10-7 %
19
Not Available
Abundance In Sun
~0.0000001 %
26
~-9999 %
Abundance In Meteorites
0.00 %
37
Not Available
Abundance In Earth's Crust
0.00 %
29
Not Available
Abundance In Oceans
0.00 %
40
Not Available
Uses
Uses & Benefits
- Magnets of Samarium cobalt alloy are stronger than that of Iron and hence, they are used in microwave application.
- Samarium metal also used in optical lasers and infrared absorbing glasses and as a neutron absorber.
- Francium has no known uses as it has a half life of only 22 minutes.
Industrial Uses
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry
NA
Medical Uses
NA
NA
Other Uses
Alloys, In Nuclear Reactors
NA
Biological Properties
Toxicity
Slightly Toxic
NA
Present in Human Body
Yes
No
In Blood
0.01 Blood/mg dm-3
22
0.00 Blood/mg dm-3
37
In Bone
Not Available
0.00 p.p.m.
36
Physical Properties
Melting Point
1,072.00 °C
99+
27.00 °C
99+
Boiling Point
1,900.00 °C
99+
677.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silvery White
NA
Luster
Lustrous
NA
Hardness
Brinell Hardness
441.00 MPa
27
Not Available
Vickers Hardness
412.00 MPa
24
Not Available
Speed of Sound
2,130.00 m/s
99+
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
Sm
Fr
Isotopes
Known Isotopes
30
9
33
6
Electronegativity
Pauling Electronegativity
1.17
40
0.70
99+
Allred Rochow Electronegativity
1.07
32
0.86
99+
Mulliken-Jaffe Electronegativity
Not Available
0.68
25
Allen Electronegativity
Not Available
0.67
99+
Electropositivity
Pauling Electropositivity
2.83
14
3.30
1
Ionization Energies
1st Energy Level
544.50 kJ/mol
99+
380.00 kJ/mol
99+
2nd Energy Level
1,070.00 kJ/mol
99+
Not Available
3rd Energy Level
2,260.00 kJ/mol
99+
Not Available
4th Energy Level
3,990.00 kJ/mol
37
Not Available
Electrochemical Equivalent
1.87 g/amp-hr
34
8.32 g/amp-hr
1
Electron Work Function
2.70 eV
99+
Not Available
Other Chemical Properties
Ionization, Radioactive Isotopes
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Atomic Properties
Atomic Number
62
99+
87
31
Electron Configuration
[Xe] 4f6 6s2
[Rn] 7s1
Crystal Structure
Rhombohedral (RHO)
Body Centered Cubic (BCC)
Crystal Lattice
RHO-Crystal-Structure-of-Samarium.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
62
99+
87
31
Number of Neutrons
88
39
136
17
Number of Electrons
62
99+
87
31
Radius of an Atom
Atomic Radius
180.00 pm
14
Not Available
Covalent Radius
198.00 pm
13
260.00 pm
1
Van der Waals Radius
229.00 pm
20
348.00 pm
1
Atomic Weight
150.36 amu
99+
223.00 amu
27
Atomic Volume
19.95 cm3/mol
19
Not Available
Adjacent Atomic Numbers
Valence Electron Potential
44.80 (-eV)
37
8.00 (-eV)
99+
Lattice Constant
362.10 pm
33
Not Available
Lattice Angles
π/2, π/2, 2 π/3
NA
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
7.52 g/cm3
99+
1.87 g/cm3
99+
Density When Liquid (at m.p.)
7.16 g/cm3
32
Not Available
Tensile Strength
Not Available
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
0.94 (Pa)
9
Not Available
Elasticity properties
Shear Modulus
19.50 GPa
34
Not Available
Bulk Modulus
37.80 GPa
35
Not Available
Young's Modulus
49.70 GPa
37
Not Available
Poisson Ratio
0.27
19
Not Available
Other Mechanical Properties
NA
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
7.52
99+
Not Available
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Poor Conductor
Resistivity
0.94 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
0.20 J/(kg K)
31
Not Available
Molar Heat Capacity
29.54 J/mol·K
7
Not Available
Thermal Conductivity
13.30 W/m·K
99+
15.00 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
12.70 µm/(m·K)
30
Not Available
Enthalpy
Enthalpy of Vaporization
166.40 kJ/mol
99+
Not Available
Enthalpy of Fusion
8.62 kJ/mol
40
Not Available
Enthalpy of Atomization
209.00 kJ/mol
99+
71.00 kJ/mol
99+
Standard Molar Entropy
69.60 J/mol.K
15
Not Available
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