Symbol
Tl
  
Fm
  
Group Number
Not Available
  
Period Number
6
  
7
  
Block
p block
  
f block
  
Element Family
Post-Transition
  
Actinide
  
Space Group Name
P63/mmc
  
Not Available
  
Space Group Number
Not Available
  
Interesting Facts
- Compounds of Thallium metal are highly Toxic.
- Thallium metal is being suspected as a human carcinogen.
  
- Fermium metal is highly radioactive in nature.
- Fermium is synthetically produced metal.
  
Sources
Found As a By-product, Ores of metals, Ores of Minerals
  
Bombarding Pu-239 with Neutrons
  
History
  
  
Who Discovered
William Crookes
  
Lawrence Berkeley National Laboratory
  
Discovery
In 1861
  
In 1952
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~0.0000001 %
  
26
~-9999 %
  
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Not Available
  
Abundance In Oceans
Not Available
  
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 Fermium metal are limited to research purpose only.
  
Industrial Uses
Chemical Industry
  
NA
  
Medical Uses
Medical Research
  
NA
  
Other Uses
Alloys
  
NA
  
Biological Properties
  
  
Toxicity
Highly Toxic
  
Unknown
  
Present in Human Body
Yes
  
No
  
In Blood
0.00 Blood/mg dm-3
  
34
0.00 Blood/mg dm-3
  
37
In Bone
0.00 p.p.m.
  
33
0.00 p.p.m.
  
36
Melting Point
1,527.00 °C
  
26
Boiling Point
1,457.00 °C
  
99+
Not Available
  
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Unknown
  
Luster
NA
  
Not Defined
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
Speed of Sound
818.00 m/s
  
99+
Not Available
  
Optical Properties
  
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Tl
  
Fm
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
589.40 kJ/mol
  
99+
627.00 kJ/mol
  
99+
2nd Energy Level
1,971.00 kJ/mol
  
14
1,225.00 kJ/mol
  
99+
3rd Energy Level
2,878.00 kJ/mol
  
32
2,363.00 kJ/mol
  
99+
4th Energy Level
Not Available
  
3,792.00 kJ/mol
  
99+
Electrochemical Equivalent
7.63 g/amp-hr
  
2
3.20 g/amp-hr
  
13
Electron Work Function
Not Available
  
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Xe] 4f14 5d10 6s2 6p1
  
[Rn] 5f12 7s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Not Known
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
Unknown-Crystal-Structure-of-Fermium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Radius
Not Available
  
Covalent Radius
Not Available
  
Atomic Volume
17.20 cm3/mol
  
31
Not Available
  
Adjacent Atomic Numbers
  
  
Valence Electron Potential
9.60 (-eV)
  
99+
Not Available
  
Lattice Constant
Not Available
  
Lattice Angles
π/2, π/2, 2 π/3
  
NA
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
11.85 g/cm
3
  
31
Not Available
  
Density When Liquid (at m.p.)
11.22 g/cm3
  
13
Not Available
  
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile, Sectile
  
NA
  
Magnetic Characteristics
  
  
Specific Gravity
Not Available
  
Magnetic Ordering
Diamagnetic
  
Unknown
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Unknown
  
Resistivity
Not Available
  
Electrical Conductivity
0.06 10
6/cm Ω
  
32
Not Available
  
Electron Affinity
19.20 kJ/mol
  
32
Not Available
  
Specific Heat
0.13 J/(kg K)
  
39
Not Available
  
Molar Heat Capacity
26.32 J/mol·K
  
29
Not Available
  
Thermal Conductivity
46.10 W/m·K
  
33
Not Available
  
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
29.90 µm/(m·K)
  
12
Not Available
  
Enthalpy
  
  
Enthalpy of Vaporization
162.10 kJ/mol
  
99+
Not Available
  
Enthalpy of Fusion
4.27 kJ/mol
  
99+
Not Available
  
Enthalpy of Atomization
179.90 kJ/mol
  
99+
Not Available
  
Standard Molar Entropy
64.20 J/mol.K
  
19
Not Available