Samarium vs Cerium
Periodic Table
Symbol
Sm
Ce
Group Number
Not Available
Not Available
Period Number
6
6
Block
f block
f block
Element Family
Lanthanide
Lanthanide
CAS Number
7440199
99+
7440451
99+
Space Group Name
R_ 3m
P63/mmc
Space Group Number
166.00
6
194.00
5
Facts
Interesting Facts
- Samarium metals helps stimulating body metabolism.
- Samarium metals was 1st observed by Jean Charles Galissard de Marignac in Dydimia in 1853.
- Cerium is a rare earth metal but still it is not rare at all.
- It’s non-toxic compound Cerium sulfide has a rich red color and it is used as a pigment.
- Cerium metal is also used in Flat screen TVs, light bulb, floodlights, etc.
Sources
Found in Minerals, Mining, Ores of Minerals
Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Lecoq de Boisbaudran
Martin Heinrich Klaproth, Jöns Jakob Berzelius, Wilhelm Hisinger
Discovery
In 1879
In 1803
Abundance
Abundance In Universe
5 * 10-7 %
19
1 * 10-6 %
16
Abundance In Sun
~0.0000001 %
26
~0.0000004 %
23
Abundance In Meteorites
0.00 %
37
0.00 %
27
Abundance In Earth's Crust
0.00 %
29
0.01 %
18
Abundance In Oceans
0.00 %
40
0.00 %
33
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.
- It is used to include flints for cigarette lighters.
- Its compound Cerium (Ill) Oxide is used as a catalyst; it is put inside the walls of the oven as it prevents from the buildup of cooking residues.
Industrial Uses
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry
Chemical Industry
Medical Uses
NA
Medical Research
Other Uses
Alloys, In Nuclear Reactors
Alloys
Biological Properties
Toxicity
Slightly Toxic
Moderately Toxic
Present in Human Body
Yes
Yes
In Blood
0.01 Blood/mg dm-3
22
0.00 Blood/mg dm-3
30
In Bone
Not Available
2.70 p.p.m.
14
Physical Properties
Melting Point
1,072.00 °C
99+
795.00 °C
99+
Boiling Point
1,900.00 °C
99+
3,257.00 °C
23
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery White
Luster
Lustrous
Lustrous
Hardness
Mohs Hardness
Not Available
2.50
14
Brinell Hardness
441.00 MPa
27
186.00 MPa
99+
Vickers Hardness
412.00 MPa
24
210.00 MPa
32
Speed of Sound
2,130.00 m/s
99+
2,100.00 m/s
99+
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
Ce
Isotopes
Known Isotopes
30
9
30
9
Electronegativity
Pauling Electronegativity
1.17
40
1.12
99+
Allred Rochow Electronegativity
1.07
32
1.08
31
Electropositivity
Pauling Electropositivity
2.83
14
2.88
11
Ionization Energies
1st Energy Level
544.50 kJ/mol
99+
534.40 kJ/mol
99+
2nd Energy Level
1,070.00 kJ/mol
99+
1,050.00 kJ/mol
99+
3rd Energy Level
2,260.00 kJ/mol
99+
1,949.00 kJ/mol
99+
4th Energy Level
3,990.00 kJ/mol
37
3,547.00 kJ/mol
99+
5th Energy Level
Not Available
6,325.00 kJ/mol
22
6th Energy Level
Not Available
7,490.00 kJ/mol
21
Electrochemical Equivalent
1.87 g/amp-hr
34
1.74 g/amp-hr
99+
Electron Work Function
2.70 eV
99+
2.84 eV
39
Other Chemical Properties
Ionization, Radioactive Isotopes
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
62
99+
58
99+
Electron Configuration
[Xe] 4f6 6s2
[Xe] 4f1 5d1 6s2
Crystal Structure
Rhombohedral (RHO)
Double Hexagonal Close Packed (DHCP)
Crystal Lattice
RHO-Crystal-Structure-of-Samarium.jpg#100
DHCP-Crystal-Structure-of-Cerium.jpg#100
Atom
Number of Protons
62
99+
58
99+
Number of Neutrons
88
39
82
99+
Number of Electrons
62
99+
58
99+
Radius of an Atom
Atomic Radius
180.00 pm
14
181.80 pm
12
Covalent Radius
198.00 pm
13
204.00 pm
8
Van der Waals Radius
229.00 pm
20
235.00 pm
17
Atomic Weight
150.36 amu
99+
140.12 amu
99+
Atomic Volume
19.95 cm3/mol
19
20.67 cm3/mol
17
Adjacent Atomic Numbers
Valence Electron Potential
44.80 (-eV)
37
41.78 (-eV)
99+
Lattice Constant
362.10 pm
33
362.00 pm
34
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, 2 π/3
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
7.52 g/cm3
99+
6.77 g/cm3
99+
Density When Liquid (at m.p.)
7.16 g/cm3
32
6.55 g/cm3
38
Tensile Strength
Not Available
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
0.94 (Pa)
9
0.00 (Pa)
34
Vapor Pressure at 2000 K
Not Available
1.04 (Pa)
13
Elasticity properties
Shear Modulus
19.50 GPa
34
13.50 GPa
99+
Bulk Modulus
37.80 GPa
35
21.50 GPa
99+
Young's Modulus
49.70 GPa
37
33.60 GPa
99+
Poisson Ratio
0.27
19
0.24
27
Other Mechanical Properties
NA
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
7.52
99+
6.77
99+
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
0.94 nΩ·m
99+
828.00 nΩ·m
3
Electrical Conductivity
0.01 106/cm Ω
99+
0.01 106/cm Ω
99+
Electron Affinity
50.00 kJ/mol
21
50.00 kJ/mol
21
Thermal Properties
Specific Heat
0.20 J/(kg K)
31
0.19 J/(kg K)
32
Molar Heat Capacity
29.54 J/mol·K
7
26.94 J/mol·K
23
Thermal Conductivity
13.30 W/m·K
99+
11.30 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
12.70 µm/(m·K)
30
6.30 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
166.40 kJ/mol
99+
414.00 kJ/mol
16
Enthalpy of Fusion
8.62 kJ/mol
40
5.46 kJ/mol
99+
Enthalpy of Atomization
209.00 kJ/mol
99+
381.00 kJ/mol
23
Standard Molar Entropy
69.60 J/mol.K
15
72.00 J/mol.K
12
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