Symbol
Tm
Pm
Group Number
33
0
17
👆🏻
Period Number
66
2
7
👆🏻
Block
f block
f block
Element Family
Lanthanide
Lanthanide
CAS Number
74403047440122
7429905
54386242
👆🏻
Space Group Name
P63/mmc
-
Space Group Number
194.00194.00
11
276
👆🏻
Interesting Facts
- Thulium metal can resist corrosion due to dry air .
- Only Tm-169 isotope of Thulium metal occur naturally.
- Promethium metal found in Pitchblende.
- Promethium metal is highly radioactive metal.
Sources
Found in Minerals, Mining, Ores of Minerals
Found in Minerals, Mining
History
Who Discovered
Per Teodor Cleve
Chien Shiung Wu, Emilio Segrè, Hans Bethe
Discovery
In 1879
In 1942
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %-
0
0.1
👆🏻
Abundance In Meteorites
0.00 %-
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
0.00 %-
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- 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.
- It is used for research purpose. Very small amount of this metal is used in atomic batteries.
- Its radioactive decay is used for a phosphor to give off light. The light emitted is converted into electricity.
Industrial Uses
-
-
Medical Uses
-
-
Other Uses
Alloys, Nuclear Research, Research Purposes
-
Biological Properties
Toxicity
-
Non Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.00 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.00 p.p.m.0.00 p.p.m.
0
170000
👆🏻
Melting Point
1,545.00 °C1,042.00 °C
-38.83
3410
👆🏻
Boiling Point
1,730.00 °C3,000.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery Gray
-
Luster
Metallic
Metallic
Hardness
Mohs Hardness
2.25-
0.2
8.5
👆🏻
Brinell Hardness
471.00 MPa400.00 MPa
0.14
3490
👆🏻
Vickers Hardness
520.00 MPa600.00 MPa
0
3920
👆🏻
Speed of Sound
2,760.00 m/s2,260.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.601.70
0.155
3.41
👆🏻
Reflectivity
35.00 %63.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Tm
Pm
Isotopes
Known Isotopes
3227
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.251.13
0
2.6
👆🏻
Sanderson Electronegativity
1.251.13
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.111.07
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.251.13
0.62
2.48
👆🏻
Allen Electronegativity
1.251.13
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.752.20
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
596.70 kJ/mol540.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,160.00 kJ/mol1,050.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,285.00 kJ/mol2,150.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
4,120.00 kJ/mol3,970.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,960.00 kJ/mol5,400.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
380
86450
👆🏻
15th Energy Level
59,600.00 kJ/mol54,000.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
59,600.00 kJ/mol54,000.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
596.70 kJ/mol540.50 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,960.00 kJ/mol5,400.00 kJ/mol
0
134810
👆🏻
19th Energy Level
596.00 kJ/mol540.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
596.00 kJ/mol540.00 kJ/mol
0
171200
👆🏻
21st Energy Level
596.70 kJ/mol540.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
596.00 kJ/mol540.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
596.70 kJ/mol540.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
596.00 kJ/mol540.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
596.00 kJ/mol540.00 kJ/mol
0
121900
👆🏻
26th Energy Level
596.70 kJ/mol540.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
596.70 kJ/mol540.00 kJ/mol
0
133800
👆🏻
28th Energy Level
596.70 kJ/mol540.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
596.00 kJ/mol540.00 kJ/mol
0
148100
👆🏻
30th Energy Level
596.70 kJ/mol540.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
2.10 g/amp-hr1.80 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
2.40 eV5.30 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
Ionization, Radioactive Isotopes, Solubility
Atomic Number
6961
3
117
👆🏻
Electron Configuration
[Xe] 4f13 6s2
[Xe] 4f5 6s2
Crystal Structure
Hexagonal Close Packed (HCP)
Double Hexagonal Close Packed (DHCP)
Crystal Lattice
Atom
Number of Protons
6961
3
117
👆🏻
Number of Neutrons
10084
4
285
👆🏻
Number of Electrons
6961
3
117
👆🏻
Radius of an Atom
Atomic Radius
176.00 pm183.00 pm
0
348
👆🏻
Covalent Radius
160.00 pm199.00 pm
0
260
👆🏻
Van der Waals Radius
227.00 pm236.00 pm
0
348
👆🏻
Atomic Weight
168.93 amu145.00 amu
6.94
294
👆🏻
Atomic Volume
18.10 cm3/mol22.39 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
49.70 (-eV)44.10 (-eV)
0
392.42
👆🏻
Lattice Constant
353.75 pm-
0
891.25
👆🏻
Lattice Angles
π/2, π/2, 2 π/3
-
Lattice C/A Ratio
1.571.63
0.423
1.9
👆🏻
Density
Density At Room Temperature
9.32 g/cm37.26 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
8.56 g/cm37.26 g/cm3
0.512
41
👆🏻
Tensile Strength
69.00 MPa75.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
0.06 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
30.50 GPa18.00 GPa
1.3
222
👆🏻
Bulk Modulus
44.50 GPa33.00 GPa
0
462
👆🏻
Young's Modulus
74.00 GPa46.00 GPa
0
528
👆🏻
Poisson Ratio
0.210.28
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile, Malleable
-
Magnetic Characteristics
Specific Gravity
9.327.26
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
676.00 nΩ·m0.75 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.02 106/cm Ω0.00 106/cm Ω
0
0.63
👆🏻
Electron Affinity
50.00 kJ/mol50.00 kJ/mol
0
222.8
👆🏻
Specific Heat
0.16 J/(kg K)0.18 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
27.03 J/mol·K27.60 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
16.90 W/m·K17.90 W/m·K
0
429
👆🏻
Critical Temperature
1,818.00 K1,315.00 K
26.3
3695
👆🏻
Thermal Expansion
13.30 µm/(m·K)9.00 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
191.00 kJ/mol289.00 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
16.80 kJ/mol7.50 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
247.00 kJ/mol310.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
74.00 J/mol.K57.00 J/mol.K
9.5
198.1
👆🏻