Symbol
La
Tm
Group Number
33
0
17
👆🏻
Period Number
66
2
7
👆🏻
Block
f block
f block
Element Family
Lanthanide
Lanthanide
CAS Number
74399107440304
7429905
54386242
👆🏻
Space Group Name
P63/mmc
P63/mmc
Space Group Number
194.00194.00
11
276
👆🏻
Interesting Facts
- Lanthanum metal is highly malleable, ductile and sectile.
- If exposed to air Lanthanum metal oxidizes rapidly.
- Thulium metal can resist corrosion due to dry air .
- Only Tm-169 isotope of Thulium metal occur naturally.
Sources
Found in Minerals, Mining, Ores of Minerals
Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Carl Gustaf Mosander
Per Teodor Cleve
Discovery
In 1838
In 1879
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %0.00 %
0
0.1
👆🏻
Abundance In Meteorites
0.00 %0.00 %
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
0.00 %0.00 %
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
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.
- Thulium metal produces isotopes that emits X-rays. This isotope is used in X-ray machine.
-
Thulium element is also used in Surgical equipment like laser.
Industrial Uses
Electrical Industry, Electronic Industry
-
Medical Uses
-
-
Other Uses
Alloys, Mirror Manufacturing
Alloys, Nuclear Research, Research Purposes
Biological Properties
Toxicity
Low Toxic
-
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.00 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.08 p.p.m.0.00 p.p.m.
0
170000
👆🏻
Melting Point
920.00 °C1,545.00 °C
-38.83
3410
👆🏻
Boiling Point
3,469.00 °C1,730.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery Gray
Luster
-
Metallic
Hardness
Mohs Hardness
2.502.25
0.2
8.5
👆🏻
Brinell Hardness
350.00 MPa471.00 MPa
0.14
3490
👆🏻
Vickers Hardness
360.00 MPa520.00 MPa
0
3920
👆🏻
Speed of Sound
2,475.00 m/s2,760.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.801.60
0.155
3.41
👆🏻
Reflectivity
70.00 %35.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
La
Tm
Isotopes
Known Isotopes
3132
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.101.25
0
2.6
👆🏻
Sanderson Electronegativity
1.101.25
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.081.11
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.101.25
0.62
2.48
👆🏻
Allen Electronegativity
1.101.25
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.902.75
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
538.10 kJ/mol596.70 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,067.00 kJ/mol1,160.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
1,850.30 kJ/mol2,285.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
4,819.00 kJ/mol4,120.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,940.00 kJ/mol5,960.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,380.00 kJ/mol5,960.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
380
86450
👆🏻
15th Energy Level
53,800.00 kJ/mol59,600.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
53,800.00 kJ/mol59,600.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
538.10 kJ/mol596.70 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,380.00 kJ/mol5,960.00 kJ/mol
0
134810
👆🏻
19th Energy Level
538.10 kJ/mol596.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
538.00 kJ/mol596.00 kJ/mol
0
171200
👆🏻
21st Energy Level
538.10 kJ/mol596.70 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
538.00 kJ/mol596.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
5,380.00 kJ/mol596.70 kJ/mol
357.6
198800
👆🏻
24th Energy Level
538.00 kJ/mol596.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
538.00 kJ/mol596.00 kJ/mol
0
121900
👆🏻
26th Energy Level
538.00 kJ/mol596.70 kJ/mol
357.6
127700
👆🏻
27th Energy Level
538.10 kJ/mol596.70 kJ/mol
0
133800
👆🏻
28th Energy Level
538.00 kJ/mol596.70 kJ/mol
297.3
139800
👆🏻
29th Energy Level
538.10 kJ/mol596.00 kJ/mol
0
148100
👆🏻
30th Energy Level
538.00 kJ/mol596.70 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.73 g/amp-hr2.10 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
3.50 eV2.40 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
Ionization, Radioactive Isotopes, Solubility
Atomic Number
5769
3
117
👆🏻
Electron Configuration
[Xe] 5d2 6s2
[Xe] 4f13 6s2
Crystal Structure
Double Hexagonal Close Packed (DHCP)
Hexagonal Close Packed (HCP)
Crystal Lattice
Atom
Number of Protons
5769
3
117
👆🏻
Number of Neutrons
82100
4
285
👆🏻
Number of Electrons
5769
3
117
👆🏻
Radius of an Atom
Atomic Radius
187.00 pm176.00 pm
0
348
👆🏻
Covalent Radius
207.00 pm160.00 pm
0
260
👆🏻
Van der Waals Radius
240.00 pm227.00 pm
0
348
👆🏻
Atomic Weight
138.91 amu168.93 amu
6.94
294
👆🏻
Atomic Volume
20.73 cm3/mol18.10 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
40.71 (-eV)49.70 (-eV)
0
392.42
👆🏻
Lattice Constant
377.20 pm353.75 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.621.57
0.423
1.9
👆🏻
Density
Density At Room Temperature
6.16 g/cm39.32 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
5.94 g/cm38.56 g/cm3
0.512
41
👆🏻
Tensile Strength
45.00 MPa69.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)0.06 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.98 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
14.30 GPa30.50 GPa
1.3
222
👆🏻
Bulk Modulus
27.90 GPa44.50 GPa
0
462
👆🏻
Young's Modulus
36.60 GPa74.00 GPa
0
528
👆🏻
Poisson Ratio
0.280.21
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile
Ductile, Malleable
Magnetic Characteristics
Specific Gravity
6.179.32
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Paramagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
615.00 nΩ·m676.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.01 106/cm Ω0.02 106/cm Ω
0
0.63
👆🏻
Electron Affinity
48.00 kJ/mol50.00 kJ/mol
0
222.8
👆🏻
Specific Heat
0.19 J/(kg K)0.16 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
27.11 J/mol·K27.03 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
13.40 W/m·K16.90 W/m·K
0
429
👆🏻
Critical Temperature
1,193.00 K1,818.00 K
26.3
3695
👆🏻
Thermal Expansion
12.10 µm/(m·K)13.30 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
399.60 kJ/mol191.00 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
6.20 kJ/mol16.80 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
431.00 kJ/mol247.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
56.90 J/mol.K74.00 J/mol.K
9.5
198.1
👆🏻