Symbol
Tl
Md
Group Number
133
0
17
👆🏻
Period Number
67
2
7
👆🏻
Block
p block
f block
Element Family
Post-Transition
Actinide
CAS Number
74402807440111
7429905
54386242
👆🏻
Space Group Name
P63/mmc
-
Space Group Number
194.00194.00
11
276
👆🏻
Interesting Facts
- Compounds of Thallium metal are highly Toxic.
- Thallium metal is being suspected as a human carcinogen.
- Mendelevium metal is synthetically produced metal.
- Mendelevium metal has been produced in only trace amount.
Sources
Found As a By-product, Ores of metals, Ores of Minerals
Bombarding Einsteinium with Helium Ions
History
Who Discovered
William Crookes
Lawrence Berkeley National Laboratory
Discovery
In 1861
In 1955
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %-
0
0.1
👆🏻
Abundance In Meteorites
0.00 %0.00 %
0
22
👆🏻
Abundance In Earth's Crust
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
- 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.
- Currently known uses of Mendelevium metal are limited to research purpose only.
Industrial Uses
Chemical Industry
-
Medical Uses
Medical Research
-
Other Uses
Alloys
-
Biological Properties
Toxicity
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
303.50 °C827.00 °C
-38.83
3410
👆🏻
Boiling Point
1,457.00 °C0.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery White
-
Luster
-
Metallic
Hardness
Mohs Hardness
1.20-
0.2
8.5
👆🏻
Brinell Hardness
26.50 MPa350.00 MPa
0.14
3490
👆🏻
Vickers Hardness
120.00 MPa0.00 MPa
0
3920
👆🏻
Speed of Sound
818.00 m/s2,680.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.901.30
0.155
3.41
👆🏻
Reflectivity
8.00 %66.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Tl
Md
Isotopes
Known Isotopes
3216
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.621.30
0
2.6
👆🏻
Sanderson Electronegativity
2.251.30
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.441.20
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.961.30
0.62
2.48
👆🏻
Allen Electronegativity
1.791.30
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.382.70
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
589.40 kJ/mol635.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,971.00 kJ/mol1,235.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,878.00 kJ/mol2,470.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
5,890.00 kJ/mol3,840.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,890.00 kJ/mol6,350.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,890.00 kJ/mol6,350.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,890.00 kJ/mol6,350.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,890.00 kJ/mol6,350.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,890.00 kJ/mol6,350.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,890.00 kJ/mol6,350.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,890.00 kJ/mol6,400.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,890.00 kJ/mol60,100.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,890.00 kJ/mol6,350.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,890.00 kJ/mol1,150.00 kJ/mol
380
86450
👆🏻
15th Energy Level
58,900.00 kJ/mol63,500.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
58,900.00 kJ/mol635.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
589.40 kJ/mol1,107.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,890.00 kJ/mol6,350.00 kJ/mol
0
134810
👆🏻
19th Energy Level
589.40 kJ/mol635.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
589.00 kJ/mol635.00 kJ/mol
0
171200
👆🏻
21st Energy Level
589.40 kJ/mol6,350.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
589.00 kJ/mol635.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
589.40 kJ/mol6,350.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
589.40 kJ/mol635.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
589.40 kJ/mol635.00 kJ/mol
0
121900
👆🏻
26th Energy Level
589.40 kJ/mol635.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
589.40 kJ/mol635.00 kJ/mol
0
133800
👆🏻
28th Energy Level
589.40 kJ/mol635.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
589.40 kJ/mol635.00 kJ/mol
0
148100
👆🏻
30th Energy Level
589.40 kJ/mol635.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
7.63 g/amp-hr3.21 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
3.84 eV3.89 eV
2.14
6
👆🏻
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Solubility
Ionization, Radioactive Isotopes, Radioactivity
Atomic Number
81101
3
117
👆🏻
Electron Configuration
[Xe] 4f14 5d10 6s2 6p1
[Rn] 5f13 7s2
Crystal Structure
Hexagonal Close Packed (HCP)
Not Known
Crystal Lattice
Atom
Number of Protons
81101
3
117
👆🏻
Number of Neutrons
123157
4
285
👆🏻
Number of Electrons
81101
3
117
👆🏻
Radius of an Atom
Atomic Radius
170.00 pm175.00 pm
0
348
👆🏻
Covalent Radius
145.00 pm175.00 pm
0
260
👆🏻
Van der Waals Radius
196.00 pm246.00 pm
0
348
👆🏻
Atomic Weight
204.38 amu258.00 amu
6.94
294
👆🏻
Atomic Volume
17.20 cm3/mol19.90 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
9.60 (-eV)63.70 (-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
1.601.58
0.423
1.9
👆🏻
Density
Density At Room Temperature
11.85 g/cm310.30 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
11.22 g/cm310.30 g/cm3
0.512
41
👆🏻
Tensile Strength
47.00 MPa80.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
16.90 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
2.80 GPa32.00 GPa
1.3
222
👆🏻
Bulk Modulus
43.00 GPa0.00 GPa
0
462
👆🏻
Young's Modulus
8.00 GPa12.00 GPa
0
528
👆🏻
Poisson Ratio
0.450.30
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile, Sectile
-
Magnetic Characteristics
Specific Gravity
11.8513.50
0.53
4500
👆🏻
Magnetic Ordering
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
-
Resistivity
0.18 nΩ·m0.63 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.06 106/cm Ω0.00 106/cm Ω
0
0.63
👆🏻
Electron Affinity
19.20 kJ/mol50.00 kJ/mol
0
222.8
👆🏻
Specific Heat
0.13 J/(kg K)0.10 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
26.32 J/mol·K27.00 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
46.10 W/m·K0.00 W/m·K
0
429
👆🏻
Critical Temperature
577.00 K1,100.00 K
26.3
3695
👆🏻
Thermal Expansion
29.90 µm/(m·K)11.60 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
162.10 kJ/mol380.50 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
4.27 kJ/mol-
2.1
35.23
👆🏻
Enthalpy of Atomization
179.90 kJ/mol410.80 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
64.20 J/mol.K37.40 J/mol.K
9.5
198.1
👆🏻