Symbol
Pm
Tl
Group Number
313
0
17
👆🏻
Period Number
66
2
7
👆🏻
Block
f block
p block
Element Family
Lanthanide
Post-Transition
CAS Number
74401227440280
7429905
54386242
👆🏻
Space Group Name
-
P63/mmc
Space Group Number
194.00194.00
11
276
👆🏻
Interesting Facts
- Promethium metal found in Pitchblende.
- Promethium metal is highly radioactive metal.
- Compounds of Thallium metal are highly Toxic.
- Thallium metal is being suspected as a human carcinogen.
Sources
Found in Minerals, Mining
Found As a By-product, Ores of metals, Ores of Minerals
History
Who Discovered
Chien Shiung Wu, Emilio Segrè, Hans Bethe
William Crookes
Discovery
In 1942
In 1861
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
- 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.
- Thallium is a toxic metal and hence it has limited uses. Thallium metal is mostly used for producing photoelectric cells.
- In thermometer’s mercury alloy has 8% of thallium, as it has a melting point lower than 20°C.
Industrial Uses
-
Chemical Industry
Medical Uses
-
Medical Research
Other Uses
-
Alloys
Biological Properties
Toxicity
Non Toxic
Highly 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
1,042.00 °C303.50 °C
-38.83
3410
👆🏻
Boiling Point
3,000.00 °C1,457.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
-
Silvery White
Luster
Metallic
-
Hardness
Mohs Hardness
-1.20
0.2
8.5
👆🏻
Brinell Hardness
400.00 MPa26.50 MPa
0.14
3490
👆🏻
Vickers Hardness
600.00 MPa120.00 MPa
0
3920
👆🏻
Speed of Sound
2,260.00 m/s818.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.701.90
0.155
3.41
👆🏻
Reflectivity
63.00 %8.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Pm
Tl
Isotopes
Known Isotopes
2732
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.131.62
0
2.6
👆🏻
Sanderson Electronegativity
1.132.25
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.071.44
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.131.96
0.62
2.48
👆🏻
Allen Electronegativity
1.131.79
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.202.38
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
540.00 kJ/mol589.40 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,050.00 kJ/mol1,971.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,150.00 kJ/mol2,878.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
3,970.00 kJ/mol5,890.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,400.00 kJ/mol5,890.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
380
86450
👆🏻
15th Energy Level
54,000.00 kJ/mol58,900.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
54,000.00 kJ/mol58,900.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
540.50 kJ/mol589.40 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,400.00 kJ/mol5,890.00 kJ/mol
0
134810
👆🏻
19th Energy Level
540.00 kJ/mol589.40 kJ/mol
375.7
148700
👆🏻
20th Energy Level
540.00 kJ/mol589.00 kJ/mol
0
171200
👆🏻
21st Energy Level
540.00 kJ/mol589.40 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
540.00 kJ/mol589.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
540.00 kJ/mol589.40 kJ/mol
357.6
198800
👆🏻
24th Energy Level
540.00 kJ/mol589.40 kJ/mol
297.3
195200
👆🏻
25th Energy Level
540.00 kJ/mol589.40 kJ/mol
0
121900
👆🏻
26th Energy Level
540.00 kJ/mol589.40 kJ/mol
357.6
127700
👆🏻
27th Energy Level
540.00 kJ/mol589.40 kJ/mol
0
133800
👆🏻
28th Energy Level
540.00 kJ/mol589.40 kJ/mol
297.3
139800
👆🏻
29th Energy Level
540.00 kJ/mol589.40 kJ/mol
0
148100
👆🏻
30th Energy Level
540.00 kJ/mol589.40 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.80 g/amp-hr7.63 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
5.30 eV3.84 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Number
6181
3
117
👆🏻
Electron Configuration
[Xe] 4f5 6s2
[Xe] 4f14 5d10 6s2 6p1
Crystal Structure
Double Hexagonal Close Packed (DHCP)
Hexagonal Close Packed (HCP)
Crystal Lattice
Atom
Number of Protons
6181
3
117
👆🏻
Number of Neutrons
84123
4
285
👆🏻
Number of Electrons
6181
3
117
👆🏻
Radius of an Atom
Atomic Radius
183.00 pm170.00 pm
0
348
👆🏻
Covalent Radius
199.00 pm145.00 pm
0
260
👆🏻
Van der Waals Radius
236.00 pm196.00 pm
0
348
👆🏻
Atomic Weight
145.00 amu204.38 amu
6.94
294
👆🏻
Atomic Volume
22.39 cm3/mol17.20 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
44.10 (-eV)9.60 (-eV)
0
392.42
👆🏻
Lattice Constant
-345.66 pm
0
891.25
👆🏻
Lattice Angles
-
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.631.60
0.423
1.9
👆🏻
Density
Density At Room Temperature
7.26 g/cm311.85 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
7.26 g/cm311.22 g/cm3
0.512
41
👆🏻
Tensile Strength
75.00 MPa47.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)16.90 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
18.00 GPa2.80 GPa
1.3
222
👆🏻
Bulk Modulus
33.00 GPa43.00 GPa
0
462
👆🏻
Young's Modulus
46.00 GPa8.00 GPa
0
528
👆🏻
Poisson Ratio
0.280.45
0.032
0.47
👆🏻
Other Mechanical Properties
-
Ductile, Sectile
Magnetic Characteristics
Specific Gravity
7.2611.85
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Diamagnetic
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
0.75 nΩ·m0.18 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.00 106/cm Ω0.06 106/cm Ω
0
0.63
👆🏻
Electron Affinity
50.00 kJ/mol19.20 kJ/mol
0
222.8
👆🏻
Specific Heat
0.18 J/(kg K)0.13 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
27.60 J/mol·K26.32 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
17.90 W/m·K46.10 W/m·K
0
429
👆🏻
Critical Temperature
1,315.00 K577.00 K
26.3
3695
👆🏻
Thermal Expansion
9.00 µm/(m·K)29.90 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
289.00 kJ/mol162.10 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
7.50 kJ/mol4.27 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
310.00 kJ/mol179.90 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
57.00 J/mol.K64.20 J/mol.K
9.5
198.1
👆🏻