Lanthanum vs Samarium
Periodic Table
Symbol
La
Sm
Group Number
Not Available
Not Available
Period Number
6
6
Block
f block
f block
Element Family
Lanthanide
Lanthanide
CAS Number
7439910
99+
7440199
99+
Space Group Name
P63/mmc
R_ 3m
Space Group Number
194.00
5
166.00
6
Facts
Interesting Facts
- Lanthanum metal is highly malleable, ductile and sectile.
- If exposed to air Lanthanum metal oxidizes rapidly.
- Samarium metals helps stimulating body metabolism.
- Samarium metals was 1st observed by Jean Charles Galissard de Marignac in Dydimia in 1853.
Sources
Found in Minerals, Mining, Ores of Minerals
Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Carl Gustaf Mosander
Lecoq de Boisbaudran
Discovery
In 1838
In 1879
Abundance
Abundance In Universe
2 * 10-7 %
22
5 * 10-7 %
19
Abundance In Sun
~0.0000002 %
25
~0.0000001 %
26
Abundance In Meteorites
0.00 %
32
0.00 %
37
Abundance In Earth's Crust
0.00 %
19
0.00 %
29
Abundance In Oceans
0.00 %
29
0.00 %
40
Uses
Uses & Benefits
- It has no commercial uses, but its alloys are in high demand. Lanthanum and Nickel alloy is used for the hydrogen gas storage.
- The best-known use for mischmetal alloy of Lanthanum is; as a ‘flints’ for cigarette lighters.
- 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.
Industrial Uses
Electrical Industry, Electronic Industry
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
NA
Other Uses
Alloys, Mirror Manufacturing
Alloys, In Nuclear Reactors
Biological Properties
Toxicity
Low Toxic
Slightly Toxic
Present in Human Body
Yes
Yes
In Blood
Not Available
0.01 Blood/mg dm-3
22
In Bone
0.08 p.p.m.
24
Not Available
Physical Properties
Melting Point
920.00 °C
99+
1,072.00 °C
99+
Boiling Point
3,469.00 °C
18
1,900.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery White
Luster
NA
Lustrous
Hardness
Mohs Hardness
2.50
14
Not Available
Brinell Hardness
350.00 MPa
30
441.00 MPa
27
Vickers Hardness
360.00 MPa
26
412.00 MPa
24
Speed of Sound
2,475.00 m/s
37
2,130.00 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
La
Sm
Isotopes
Known Isotopes
31
8
30
9
Electronegativity
Pauling Electronegativity
1.10
99+
1.17
40
Allred Rochow Electronegativity
1.08
31
1.07
32
Electropositivity
Pauling Electropositivity
2.90
10
2.83
14
Ionization Energies
1st Energy Level
538.10 kJ/mol
99+
544.50 kJ/mol
99+
2nd Energy Level
1,067.00 kJ/mol
99+
1,070.00 kJ/mol
99+
3rd Energy Level
1,850.30 kJ/mol
99+
2,260.00 kJ/mol
99+
4th Energy Level
4,819.00 kJ/mol
22
3,990.00 kJ/mol
37
5th Energy Level
5,940.00 kJ/mol
25
Not Available
Electrochemical Equivalent
1.73 g/amp-hr
99+
1.87 g/amp-hr
34
Electron Work Function
3.50 eV
31
2.70 eV
99+
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
Ionization, Radioactive Isotopes
Atomic Properties
Atomic Number
57
99+
62
99+
Electron Configuration
[Xe] 5d2 6s2
[Xe] 4f6 6s2
Crystal Structure
Double Hexagonal Close Packed (DHCP)
Rhombohedral (RHO)
Crystal Lattice
DHCP-Crystal-Structure-of-Lanthanum.jpg#100
RHO-Crystal-Structure-of-Samarium.jpg#100
Atom
Number of Protons
57
99+
62
99+
Number of Neutrons
82
99+
88
39
Number of Electrons
57
99+
62
99+
Radius of an Atom
Atomic Radius
187.00 pm
8
180.00 pm
14
Covalent Radius
207.00 pm
6
198.00 pm
13
Van der Waals Radius
240.00 pm
13
229.00 pm
20
Atomic Weight
138.91 amu
99+
150.36 amu
99+
Atomic Volume
20.73 cm3/mol
16
19.95 cm3/mol
19
Adjacent Atomic Numbers
Valence Electron Potential
40.71 (-eV)
99+
44.80 (-eV)
37
Lattice Constant
377.20 pm
28
362.10 pm
33
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.62
2
Not Available
Mechanical Properties
Density
Density At Room Temperature
6.16 g/cm3
99+
7.52 g/cm3
99+
Density When Liquid (at m.p.)
5.94 g/cm3
99+
7.16 g/cm3
32
Tensile Strength
Not Available
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
Not Available
0.94 (Pa)
9
Vapor Pressure at 2000 K
0.98 (Pa)
15
Not Available
Elasticity properties
Shear Modulus
14.30 GPa
40
19.50 GPa
34
Bulk Modulus
27.90 GPa
99+
37.80 GPa
35
Young's Modulus
36.60 GPa
99+
49.70 GPa
37
Poisson Ratio
0.28
17
0.27
19
Other Mechanical Properties
Ductile
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
6.17
99+
7.52
99+
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
615.00 nΩ·m
7
0.94 nΩ·m
99+
Electrical Conductivity
0.01 106/cm Ω
99+
0.01 106/cm Ω
99+
Electron Affinity
48.00 kJ/mol
23
50.00 kJ/mol
21
Thermal Properties
Specific Heat
0.19 J/(kg K)
32
0.20 J/(kg K)
31
Molar Heat Capacity
27.11 J/mol·K
21
29.54 J/mol·K
7
Thermal Conductivity
13.40 W/m·K
99+
13.30 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
12.10 µm/(m·K)
32
12.70 µm/(m·K)
30
Enthalpy
Enthalpy of Vaporization
399.60 kJ/mol
17
166.40 kJ/mol
99+
Enthalpy of Fusion
6.20 kJ/mol
99+
8.62 kJ/mol
40
Enthalpy of Atomization
431.00 kJ/mol
16
209.00 kJ/mol
99+
Standard Molar Entropy
56.90 J/mol.K
23
69.60 J/mol.K
15
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