Properties of Cesium and Actinium
Melting Point
1,227.00 °C
  
38
Boiling Point
3,200.00 °C
  
26
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
Vickers Hardness
Not Available
  
Not Available
  
Optical Properties
  
  
Refractive Index
Not Available
  
Not Available
  
Reflectivity
Not Available
  
Not Available
  
Speed of Sound
Not Available
  
Not Available
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Cs
  
Ac
  
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
375.70 kJ/mol
  
99+
499.00 kJ/mol
  
99+
2nd Energy Level
2,234.30 kJ/mol
  
8
1,170.00 kJ/mol
  
99+
3rd Energy Level
3,400.00 kJ/mol
  
16
1,900.00 kJ/mol
  
99+
Electrochemical Equivalent
4.96 g/amp-hr
  
3
2.82 g/amp-hr
  
18
Electron Work Function
Not Available
  
Other Chemical Properties
Density
  
  
Density At Room Temperature
1.93 g/cm3
  
99+
10.00 g/cm3
  
37
Density When Liquid (at m.p.)
1.84 g/cm3
  
99+
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Not Available
  
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Not Available
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Not Available
  
Other Mechanical Properties
NA
  
Symbol
Cs
  
Ac
  
Group Number
Not Available
  
Period Number
6
  
7
  
Atomic Weight
132.91 amu
  
99+
Atomic Volume
71.07 cm3/mol
  
1
22.54 cm3/mol
  
11
Electron Configuration
[Xe] 6s1
  
[Rn] 6d1 7s2
  
Valence Electron Potential
8.62 (-eV)
  
99+
38.60 (-eV)
  
99+
Atom
  
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
FCC-Crystal-Structure-of-Actinium.jpg#100
  
Radius of an Atom
  
  
Covalent Radius
Not Available
  
Van der Waals Radius
Not Available
  
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Adjacent Atomic Numbers
  
  
Electrical Properties
  
  
Resistivity
205.00 nΩ·m
  
17
Not Available
  
Electrical Conductivity
0.05 10
6/cm Ω
  
35
Not Available
  
Electron Affinity
45.50 kJ/mol
  
25
Not Available
  
Electrical Property
Unknown
  
Magnetic Characteristics
  
  
Permeability
Not Available
  
Not Available
  
Susceptibility
Not Available
  
Not Available
  
Specific Heat
0.24 J/(kg K)
  
23
0.12 J/(kg K)
  
40
Thermal Conductivity
35.90 W/m·K
  
36
12.00 W/m·K
  
99+
Critical Temperature
Not Available
  
Molar Heat Capacity
32.21 J/mol·K
  
4
27.20 J/mol·K
  
18
Thermal Expansion
97.00 µm/(m·K)
  
1
Not Available
  
Standard Molar Entropy
85.20 J/mol.K
  
3
56.50 J/mol.K
  
25
Enthalpy
  
  
Enthalpy of Vaporization
65.90 kJ/mol
  
99+
Not Available
  
Enthalpy of Fusion
2.10 kJ/mol
  
99+
Not Available
  
Enthalpy of Atomization
78.20 kJ/mol
  
99+
301.00 kJ/mol
  
36