Properties of Potassium and Thallium
Boiling Point
1,457.00 °C
  
99+
Hardness
  
  
Vickers Hardness
Not Available
  
Not Available
  
Optical Properties
  
  
Refractive Index
Not Available
  
Not Available
  
Reflectivity
Not Available
  
Not Available
  
Speed of Sound
2,000.00 m/s
  
99+
818.00 m/s
  
99+
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
K
  
Tl
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
418.80 kJ/mol
  
99+
589.40 kJ/mol
  
99+
2nd Energy Level
3,052.00 kJ/mol
  
5
1,971.00 kJ/mol
  
14
3rd Energy Level
4,420.00 kJ/mol
  
8
2,878.00 kJ/mol
  
32
Electrochemical Equivalent
1.46 g/amp-hr
  
99+
7.63 g/amp-hr
  
2
Other Chemical Properties
Density
  
  
Density At Room Temperature
0.86 g/cm3
  
99+
11.85 g/cm3
  
31
Density When Liquid (at m.p.)
0.83 g/cm3
  
99+
11.22 g/cm3
  
13
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Not Available
  
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Elasticity properties
  
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
NA
  
Symbol
K
  
Tl
  
Period Number
4
  
6
  
Atomic Volume
45.46 cm3/mol
  
3
17.20 cm3/mol
  
31
Electron Configuration
[Ar] 4s1
  
[Xe] 4f14 5d10 6s2 6p1
  
Valence Electron Potential
10.40 (-eV)
  
99+
9.60 (-eV)
  
99+
Atom
  
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Radius of an Atom
  
  
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, 2 π/3
  
Lattice C/A Ratio
Not Available
  
Adjacent Atomic Numbers
  
  
Electrical Properties
  
  
Electrical Conductivity
0.14 106/cm Ω
  
14
0.06 106/cm Ω
  
32
Electron Affinity
48.40 kJ/mol
  
22
19.20 kJ/mol
  
32
Magnetic Characteristics
  
  
Permeability
Not Available
  
Not Available
  
Susceptibility
Not Available
  
Not Available
  
Specific Heat
0.75 J/(kg K)
  
6
0.13 J/(kg K)
  
39
Thermal Conductivity
102.50 W/m·K
  
15
46.10 W/m·K
  
33
Critical Temperature
Not Available
  
Molar Heat Capacity
29.60 J/mol·K
  
6
26.32 J/mol·K
  
29
Thermal Expansion
83.30 µm/(m·K)
  
3
29.90 µm/(m·K)
  
12
Standard Molar Entropy
64.70 J/mol.K
  
18
64.20 J/mol.K
  
19
Enthalpy
  
  
Enthalpy of Vaporization
77.50 kJ/mol
  
99+
162.10 kJ/mol
  
99+
Enthalpy of Fusion
2.32 kJ/mol
  
99+
4.27 kJ/mol
  
99+
Enthalpy of Atomization
89.50 kJ/mol
  
99+
179.90 kJ/mol
  
99+