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Cesium Rubidium Comparison


Rubidium Cesium comparison


Periodic Table

Symbol
Cs   
Rb   

Group Number
1   
17
1   
17

Period Number
6   
5   

Block
s block   
s block   

Element Family
Alkali   
Alkali   

CAS Number
7440462   
40
7440177   
99+

Space Group Name
Im_ 3m   
Im_ 3m   

Space Group Number
229.00   
1
229.00   
1

Facts

Interesting Facts
Not Available   
  • Rubidium metal is 16th most common element found in the earth crust.
  • Rubidium metal also found in minerals as well as seawater.
  

Sources
Earth's crust, Found in Minerals, Mining, Ores of Minerals   
Obtained from Lithium Production.   

History
  
  

Who Discovered
Robert Bunsen and Gustav Kirchhoff   
Robert Bunsen and Gustav Kirchhoff   

Discovery
In 1860   
In 1861   

Abundance
  
  

Abundance In Universe
8 * 10-8 %   
24
1 * 10-6 %   
16

Abundance In Sun
~0.0000008 %   
20
~0.000003 %   
17

Abundance In Meteorites
0.00 %   
38
0.00 %   
19

Abundance In Earth's Crust
0.00 %   
35
0.01 %   
18

Abundance In Oceans
0.00 %   
17
0.00 %   
7

Abundance In Humans
0.00 %   
17
0.00 %   
7

Uses

Uses & Benefits
  • The most common use of cesium metal is as a drilling fluid. It is also used in optical glass manufacturing.
  • In vacuum tubes and radiation monitor equipment this metal is used as a catalyst promoter.
  
  • Rubidium's main application is in the glass manufacturing.
  • Rubidium can very easily get ionized and hence it is used for ion engines, but it is still less efficient than that of Caesium.
  

Industrial Uses
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys   
Alloys, Research Purposes   

Biological Properties
  
  

Toxicity
Mildly Toxic   
Non Toxic   

Present in Human Body
Yes   
Yes   

In Blood
0.00 Blood/mg dm-3   
28
2.49 Blood/mg dm-3   
7

In Bone
0.05 p.p.m.   
26
5.00 p.p.m.   
13

Physical Properties

Melting Point
28.50 °C   
99+
38.89 °C   
99+

Boiling Point
678.40 °C   
99+
688.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery Gold   
Grayish White   

Luster
NA   
NA   

Hardness
  
  

Mohs Hardness
0.20   
25
0.30   
24

Brinell Hardness
0.14 MPa   
99+
0.22 MPa   
99+

Speed of Sound
Not Available   
1,300.00 m/s   
99+

Optical Properties
  
  

Allotropes
No   
No   

α Allotropes
Not Available   
Not Available   

β Allotropes
Not Available   
Not Available   

γ Allotropes
Not Available   
Not Available   

Chemical Properties

Chemical Formula
Cs   
Rb   

Isotopes
  
  

Known Isotopes
36   
3
29   
10

Electronegativity
  
  

Pauling Electronegativity
0.79   
99+
0.82   
99+

Sanderson Electronegativity
0.22   
33
0.31   
32

Allred Rochow Electronegativity
0.86   
99+
0.89   
40

Mulliken-Jaffe Electronegativity
0.62   
26
0.69   
24

Allen Electronegativity
0.66   
99+
0.71   
99+

Electropositivity
  
  

Pauling Electropositivity
3.21   
2
3.18   
3

Ionization Energies
  
  

1st Energy Level
375.70 kJ/mol   
99+
403.00 kJ/mol   
99+

2nd Energy Level
2,234.30 kJ/mol   
8
2,633.00 kJ/mol   
6

3rd Energy Level
3,400.00 kJ/mol   
16
3,860.00 kJ/mol   
11

4th Energy Level
Not Available   
5,080.00 kJ/mol   
18

5th Energy Level
Not Available   
6,850.00 kJ/mol   
19

6th Energy Level
Not Available   
8,140.00 kJ/mol   
20

7th Energy level
Not Available   
9,570.00 kJ/mol   
20

8th Energy Level
Not Available   
13,120.00 kJ/mol   
17

9th Energy Level
Not Available   
14,500.00 kJ/mol   
18

10th Energy Level
Not Available   
26,740.00 kJ/mol   
6

Electrochemical Equivalent
4.96 g/amp-hr   
3
3.19 g/amp-hr   
14

Electron Work Function
2.14 eV   
99+
2.16 eV   
99+

Other Chemical Properties
Chemical Stability, Corrosion, Ionization, Radioactive Isotopes, Solubility   
Corrosion, Ionization, Radioactive Isotopes, Radioactivity   

Atomic Properties

Atomic Number
55   
99+
37   
99+

Electron Configuration
[Xe] 6s1   
[Kr] 5s1   

Crystal Structure
Body Centered Cubic (BCC)   
Body Centered Cubic (BCC)   

Crystal Lattice
BCC-Crystal-Structure-.jpg#100   
BCC-Crystal-Structure-.jpg#100   

Atom
  
  

Number of Protons
55   
99+
37   
99+

Number of Neutrons
78   
99+
48   
99+

Number of Electrons
55   
99+
37   
99+

Radius of an Atom
  
  

Atomic Radius
265.00 pm   
1
248.00 pm   
2

Covalent Radius
244.00 pm   
2
220.00 pm   
4

Van der Waals Radius
343.00 pm   
2
303.00 pm   
3

Atomic Weight
132.91 amu   
99+
85.47 amu   
99+

Atomic Volume
71.07 cm3/mol   
1
55.90 cm3/mol   
2

Adjacent Atomic Numbers
  
  

Previous Element
Tin
  
Gallium
  

Next Element
Barium
  
Strontium
  

Valence Electron Potential
8.62 (-eV)   
99+
9.47 (-eV)   
99+

Lattice Constant
614.10 pm   
5
558.50 pm   
10

Lattice Angles
π/2, π/2, π/2   
π/2, π/2, π/2   

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
1.93 g/cm3   
99+
1.53 g/cm3   
99+

Density When Liquid (at m.p.)
1.84 g/cm3   
99+
1.46 g/cm3   
99+

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Elasticity properties
  
  

Bulk Modulus
1.60 GPa   
99+
2.50 GPa   
99+

Young's Modulus
1.70 GPa   
99+
2.40 GPa   
99+

Poisson Ratio
Not Available   
Not Available   

Other Mechanical Properties
Ductile   
Ductile   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
1.87   
99+
1.53   
99+

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Semiconductor   
Conductor   

Resistivity
205.00 nΩ·m   
17
128.00 nΩ·m   
26

Electrical Conductivity
0.05 106/cm Ω   
35
0.08 106/cm Ω   
24

Electron Affinity
45.50 kJ/mol   
25
46.90 kJ/mol   
24

Thermal Properties

Specific Heat
0.24 J/(kg K)   
23
0.36 J/(kg K)   
17

Molar Heat Capacity
32.21 J/mol·K   
4
31.06 J/mol·K   
5

Thermal Conductivity
35.90 W/m·K   
36
58.20 W/m·K   
26

Critical Temperature
1,938.00 K   
5
2,093.00 K   
4

Thermal Expansion
97.00 µm/(m·K)   
1
90.00 µm/(m·K)   
2

Enthalpy
  
  

Enthalpy of Vaporization
65.90 kJ/mol   
99+
69.20 kJ/mol   
99+

Enthalpy of Fusion
2.10 kJ/mol   
99+
2.19 kJ/mol   
99+

Enthalpy of Atomization
78.20 kJ/mol   
99+
82.00 kJ/mol   
99+

Standard Molar Entropy
85.20 J/mol.K   
3
76.80 J/mol.K   
5

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