Home
 Compare Metals

Rubidium vs Francium

Rubidium
Francium
Francium vs Rubidium


Periodic Table
Symbol
Rb  
Fr  
Group Number
1  
17
1  
17
Period Number
5  
7  
Block
s block  
s block  
Element Family
Alkali  
Alkali  
CAS Number
7440177  
99+
7440735  
18
Space Group Name
Im_ 3m  
-  
Space Group Number
229.00  
2
225.00  
3
Facts
Interesting Facts
  • Rubidium metal is 16th most common element found in the earth crust.
  • Rubidium metal also found in minerals as well as seawater.
  
  • 223 Francium has the longest half life at 21.8.
  • Francium metal is produced by alpha decay in 227Actinium 227.
  
Sources
Obtained from Lithium Production.  
Formed by Decay Process, Mining  
History
  
  
Who Discovered
Robert Bunsen and Gustav Kirchhoff  
Marguerite Perey  
Discovery
In 1861  
In 1939  
Abundance
  
  
Abundance In Universe
0.00 %  
17
0.00 %  
40
Abundance In Sun
0.00 %  
17
0.00 %  
30
Abundance In Meteorites
0.00 %  
19
0.00 %  
99+
Abundance In Earth's Crust
0.01 %  
18
0.00 %  
99+
Abundance In Oceans
0.00 %  
7
-  
Abundance In Humans
0.00 %  
8
0.00 %  
24
Uses
Uses & Benefits
  • 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.
  
  • Francium has no known uses as it has a half life of only 22 minutes.
  
Industrial Uses
-  
-  
Medical Uses
-  
-  
Other Uses
Alloys, Research Purposes  
-  
Biological Properties
  
  
Toxicity
Non Toxic  
-  
Present in Human Body
Yes  
No  
In Blood
2.49 Blood/mg dm-3  
7
0.00 Blood/mg dm-3  
40
In Bone
5.00 p.p.m.  
13
0.00 p.p.m.  
99+
Physical
Melting Point
38.89 °C  
99+
27.00 °C  
99+
Boiling Point
688.00 °C  
99+
677.00 °C  
99+
Appearance
  
  
Physical State
Solid  
Solid  
Color
Grayish White  
-  
Luster
-  
-  
Hardness
  
  
Mohs Hardness
0.30  
26
0.20  
27
Brinell Hardness
0.22 MPa  
99+
119.00 MPa  
99+
Vickers Hardness
0.22 MPa  
99+
300.00 MPa  
99+
Speed of Sound
1,300.00 m/s  
99+
2,440.00 m/s  
99+
Optical Properties
  
  
Refractive Index
1.54  
35
1.70  
27
Reflectivity
52.00 %  
29
72.00 %  
11
Allotropes
No  
No  
α Allotropes
-  
-  
β Allotropes
-  
-  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Rb  
Fr  
Isotopes
  
  
Known Isotopes
29  
10
33  
6
Electronegativity
  
  
Pauling Electronegativity
0.82  
99+
0.70  
99+
Sanderson Electronegativity
0.31  
99+
0.70  
99+
Allred Rochow Electronegativity
0.89  
99+
0.86  
99+
Mulliken-Jaffe Electronegativity
0.69  
99+
0.68  
99+
Allen Electronegativity
0.71  
99+
0.67  
99+
Electropositivity
  
  
Pauling Electropositivity
3.18  
3
3.30  
1
Ionization Energies
  
  
1st Energy Level
403.00 kJ/mol  
99+
380.00 kJ/mol  
99+
2nd Energy Level
2,633.00 kJ/mol  
6
392.80 kJ/mol  
99+
3rd Energy Level
3,860.00 kJ/mol  
11
392.80 kJ/mol  
99+
4th Energy Level
5,080.00 kJ/mol  
28
392.80 kJ/mol  
99+
5th Energy Level
6,850.00 kJ/mol  
31
392.00 kJ/mol  
99+
6th Energy Level
8,140.00 kJ/mol  
31
3,920.00 kJ/mol  
99+
7th Energy level
9,570.00 kJ/mol  
20
3,920.00 kJ/mol  
99+
8th Energy Level
13,120.00 kJ/mol  
17
3,920.00 kJ/mol  
99+
9th Energy Level
14,500.00 kJ/mol  
18
3,920.00 kJ/mol  
99+
10th Energy Level
26,740.00 kJ/mol  
6
392.00 kJ/mol  
99+
11th Energy Level
4,030.00 kJ/mol  
99+
392.00 kJ/mol  
99+
12th Energy Level
4,030.00 kJ/mol  
99+
38,000.00 kJ/mol  
23
13th Energy Level
4,030.00 kJ/mol  
99+
3,920.00 kJ/mol  
99+
14th Energy Level
4,030.00 kJ/mol  
99+
380.00 kJ/mol  
99+
15th Energy Level
40,300.00 kJ/mol  
99+
67,700.00 kJ/mol  
32
16th Energy Level
40,300.00 kJ/mol  
99+
39,200.00 kJ/mol  
99+
17th Energy Level
403.00 kJ/mol  
99+
392.00 kJ/mol  
99+
18th Energy Level
4,030.00 kJ/mol  
99+
3,920.00 kJ/mol  
99+
19th Energy Level
403.00 kJ/mol  
99+
392.80 kJ/mol  
99+
20th Energy Level
403.00 kJ/mol  
99+
392.00 kJ/mol  
99+
21st Energy Level
403.00 kJ/mol  
99+
392.00 kJ/mol  
99+
22nd Energy Level
403.00 kJ/mol  
99+
392.00 kJ/mol  
99+
23rd Energy Level
403.00 kJ/mol  
99+
392.80 kJ/mol  
99+
24th Energy Level
403.00 kJ/mol  
99+
392.00 kJ/mol  
99+
25th Energy Level
403.00 kJ/mol  
99+
392.00 kJ/mol  
99+
26th Energy Level
403.00 kJ/mol  
99+
392.80 kJ/mol  
99+
27th Energy Level
403.00 kJ/mol  
99+
392.00 kJ/mol  
99+
28th Energy Level
403.00 kJ/mol  
99+
380.00 kJ/mol  
99+
29th Energy Level
403.00 kJ/mol  
99+
392.00 kJ/mol  
99+
30th Energy Level
403.00 kJ/mol  
99+
677.00 kJ/mol  
31
Electrochemical Equivalent
3.19 g/amp-hr  
16
8.32 g/amp-hr  
1
Electron Work Function
2.16 eV  
99+
4.07 eV  
33
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity  
Ionization, Radioactive Isotopes, Radioactivity, Solubility  
Atomic
Atomic Number
37  
99+
87  
31
Electron Configuration
[Kr] 5s1  
[Rn] 7s1  
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
37  
99+
87  
31
Number of Neutrons
48  
99+
136  
18
Number of Electrons
37  
99+
87  
31
Radius of an Atom
  
  
Atomic Radius
248.00 pm  
3
348.00 pm  
1
Covalent Radius
220.00 pm  
4
260.00 pm  
1
Van der Waals Radius
303.00 pm  
4
348.00 pm  
1
Atomic Weight
85.47 amu  
99+
223.00 amu  
27
Atomic Volume
55.90 cm3/mol  
3
71.00 cm3/mol  
2
Adjacent Atomic Numbers
  
  
Previous Element
Gallium
  
Polonium
  
Next Element
Strontium
  
Radium
  
Valence Electron Potential
9.47 (-eV)  
99+
8.00 (-eV)  
99+
Lattice Constant
558.50 pm  
11
440.00 pm  
21
Lattice Angles
π/2, π/2, π/2  
-  
Lattice C/A Ratio
1.59  
28
1.56  
99+
Mechanical
Density
  
  
Density At Room Temperature
1.53 g/cm3  
99+
1.87 g/cm3  
99+
Density When Liquid (at m.p.)
1.46 g/cm3  
99+
1.87 g/cm3  
99+
Tensile Strength
30.00 MPa  
99+
50.00 MPa  
38
Viscosity
0.00  
23
0.00  
25
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
37
0.00 (Pa)  
37
Vapor Pressure at 2000 K
0.00 (Pa)  
35
0.00 (Pa)  
24
Elasticity properties
  
  
Shear Modulus
2.50 GPa  
99+
3.60 GPa  
99+
Bulk Modulus
2.50 GPa  
99+
6.00 GPa  
99+
Young's Modulus
2.40 GPa  
99+
0.00 GPa  
99+
Poisson Ratio
0.37  
7
0.44  
3
Other Mechanical Properties
Ductile  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
1.53  
99+
0.87  
99+
Magnetic Ordering
Paramagnetic  
Paramagnetic  
Permeability
0.00 H/m  
11
0.00 H/m  
13
Susceptibility
0.00  
24
0.00  
24
Electrical Properties
  
  
Electrical Property
Conductor  
Poor Conductor  
Resistivity
128.00 nΩ·m  
26
3.00 nΩ·m  
99+
Electrical Conductivity
0.08 106/cm Ω  
29
0.03 106/cm Ω  
99+
Electron Affinity
46.90 kJ/mol  
29
0.70 kJ/mol  
99+
Thermal
Specific Heat
0.36 J/(kg K)  
17
0.15 J/(kg K)  
37
Molar Heat Capacity
31.06 J/mol·K  
7
27.00 J/mol·K  
29
Thermal Conductivity
58.20 W/m·K  
26
15.00 W/m·K  
99+
Critical Temperature
2,093.00 K  
18
300.00 K  
99+
Thermal Expansion
90.00 µm/(m·K)  
2
18.90 µm/(m·K)  
25
Enthalpy
  
  
Enthalpy of Vaporization
69.20 kJ/mol  
99+
67.00 kJ/mol  
99+
Enthalpy of Fusion
2.19 kJ/mol  
99+
2.30 kJ/mol  
99+
Enthalpy of Atomization
82.00 kJ/mol  
99+
71.00 kJ/mol  
99+
Standard Molar Entropy
76.80 J/mol.K  
5
42.00 J/mol.K  
99+
Periodic Table >>
<< All

Compare Alkali Metals

Alkali Metals

Alkali Metals

» More Alkali Metals

Compare Alkali Metals

» More Compare Alkali Metals
Home | About | Contact | Disclaimer | Terms of use
© A softusvista inc. venture!