Symbol
Rb
  
Ra
  
Period Number
5
  
7
  
Block
s block
  
s block
  
Element Family
Alkali
  
Alkaline Earth
  
Space Group Name
Im_ 3m
  
Im_ 3m
  
Interesting Facts
- Rubidium metal is 16th most common element found in the earth crust.
- Rubidium metal also found in minerals as well as seawater.
  
- Radium metal is the heaviest metal of Alkaline earth metals column.
- Radium metal is highly radioactive and does not have any stable isotopes.
  
Sources
Obtained from Lithium Production.
  
Mining, Ores of metals
  
History
  
  
Who Discovered
Robert Bunsen and Gustav Kirchhoff
  
Not Available
  
Discovery
In 1861
  
In 1898
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~0.000003 %
  
17
~-9999 %
  
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
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.
  
- It is a highly radioactive metal; and sometime Radium-223 is used to treat prostate cancer.
-
It is used in luminous paints.
  
Industrial Uses
NA
  
NA
  
Medical Uses
NA
  
Pharmaceutical Industry
  
Other Uses
Alloys, Research Purposes
  
NA
  
Biological Properties
  
  
Toxicity
Non Toxic
  
Highly Toxic
  
Present in Human Body
Yes
  
No
  
In Blood
2.49 Blood/mg dm-3
  
7
Not Available
  
In Bone
5.00 p.p.m.
  
13
Not Available
  
Boiling Point
1,737.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Grayish White
  
Silvery White
  
Luster
NA
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
Speed of Sound
1,300.00 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
Rb
  
Ra
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
403.00 kJ/mol
  
99+
509.30 kJ/mol
  
99+
2nd Energy Level
2,633.00 kJ/mol
  
6
979.00 kJ/mol
  
99+
3rd Energy Level
3,860.00 kJ/mol
  
11
Not Available
  
4th Energy Level
5,080.00 kJ/mol
  
18
Not Available
  
5th Energy Level
6,850.00 kJ/mol
  
19
Not Available
  
6th Energy Level
8,140.00 kJ/mol
  
20
Not Available
  
7th Energy level
9,570.00 kJ/mol
  
20
Not Available
  
8th Energy Level
13,120.00 kJ/mol
  
17
Not Available
  
9th Energy Level
14,500.00 kJ/mol
  
18
Not Available
  
10th Energy Level
26,740.00 kJ/mol
  
6
Not Available
  
Electrochemical Equivalent
3.19 g/amp-hr
  
14
4.22 g/amp-hr
  
6
Electron Work Function
Not Available
  
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
  
Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Kr] 5s1
  
[Rn] 7s2
  
Crystal Structure
Body Centered Cubic (BCC)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Radius
Not Available
  
Atomic Volume
55.90 cm3/mol
  
2
45.20 cm3/mol
  
4
Adjacent Atomic Numbers
  
  
Valence Electron Potential
9.47 (-eV)
  
99+
20.10 (-eV)
  
99+
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
1.53 g/cm3
  
99+
5.50 g/cm3
  
99+
Density When Liquid (at m.p.)
1.46 g/cm3
  
99+
Not Available
  
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Not Available
  
Other Mechanical Properties
Ductile
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Nonmagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
NA
  
Resistivity
128.00 nΩ·m
  
26
100.00 nΩ·m
  
31
Electrical Conductivity
0.08 10
6/cm Ω
  
24
Not Available
  
Electron Affinity
46.90 kJ/mol
  
24
Not Available
  
Specific Heat
0.36 J/(kg K)
  
17
0.12 J/(kg K)
  
40
Molar Heat Capacity
31.06 J/mol·K
  
5
Not Available
  
Thermal Conductivity
58.20 W/m·K
  
26
18.60 W/m·K
  
99+
Critical Temperature
Not Available
  
Thermal Expansion
90.00 µm/(m·K)
  
2
Not Available
  
Enthalpy
  
  
Enthalpy of Vaporization
69.20 kJ/mol
  
99+
Not Available
  
Enthalpy of Fusion
2.19 kJ/mol
  
99+
Not Available
  
Enthalpy of Atomization
82.00 kJ/mol
  
99+
163.00 kJ/mol
  
99+
Standard Molar Entropy
76.80 J/mol.K
  
5
71.00 J/mol.K
  
14