Symbol
Rb
  
Ca
  
Period Number
5
  
4
  
Block
s block
  
s block
  
Element Family
Alkali
  
Alkaline Earth
  
Space Group Name
Im_ 3m
  
Fm_ 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.
  
- Calcium ranks 5th rank in the list of earth’s abundance Percentage.
- It is found in the compound state.
- Gypsum or calcium sulfate is used as plaster and plaster of paris.
  
Sources
Obtained from Lithium Production.
  
Earth's crust, Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Robert Bunsen and Gustav Kirchhoff
  
Humphry Davy
  
Discovery
In 1861
  
In 1808
  
Abundance
  
  
Abundance In Sun
~0.000003 %
  
17
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 used as a reducing agent while preparing metals like thorium and uranium. It is also used as an alloying agent for metals such as aluminum, copper & lead.
- Calcium carbonate or lime stone is used in cement.
  
Industrial Uses
NA
  
Chemical Industry
  
Medical Uses
NA
  
Dentistry, Pharmaceutical Industry
  
Other Uses
Alloys, Research Purposes
  
Alloys
  
Biological Properties
  
  
Toxicity
Non Toxic
  
Non Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
2.49 Blood/mg dm-3
  
7
60.50 Blood/mg dm-3
  
4
In Bone
5.00 p.p.m.
  
13
170,000.00 p.p.m.
  
1
Boiling Point
1,484.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Grayish White
  
Gray
  
Luster
NA
  
NA
  
Hardness
  
  
Brinell Hardness
170.00 MPa
  
99+
Speed of Sound
1,300.00 m/s
  
99+
3,810.00 m/s
  
19
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
  
Ca
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
403.00 kJ/mol
  
99+
589.80 kJ/mol
  
99+
2nd Energy Level
2,633.00 kJ/mol
  
6
1,145.40 kJ/mol
  
99+
3rd Energy Level
3,860.00 kJ/mol
  
11
4,912.40 kJ/mol
  
7
4th Energy Level
5,080.00 kJ/mol
  
18
6,491.00 kJ/mol
  
7
5th Energy Level
6,850.00 kJ/mol
  
19
8,153.00 kJ/mol
  
7
6th Energy Level
8,140.00 kJ/mol
  
20
10,496.00 kJ/mol
  
8
7th Energy level
9,570.00 kJ/mol
  
20
12,270.00 kJ/mol
  
12
8th Energy Level
13,120.00 kJ/mol
  
17
14,206.00 kJ/mol
  
15
9th Energy Level
14,500.00 kJ/mol
  
18
18,191.00 kJ/mol
  
12
10th Energy Level
26,740.00 kJ/mol
  
6
20,385.00 kJ/mol
  
16
11th Energy Level
Not Available
  
57,110.00 kJ/mol
  
3
12th Energy Level
Not Available
  
63,410.00 kJ/mol
  
3
13th Energy Level
Not Available
  
70,110.00 kJ/mol
  
3
14th Energy Level
Not Available
  
78,890.00 kJ/mol
  
4
15th Energy Level
Not Available
  
86,310.00 kJ/mol
  
5
16th Energy Level
Not Available
  
94,000.00 kJ/mol
  
6
17th Energy Level
Not Available
  
104,900.00 kJ/mol
  
7
18th Energy Level
Not Available
  
111,711.00 kJ/mol
  
8
Electrochemical Equivalent
3.19 g/amp-hr
  
14
0.75 g/amp-hr
  
99+
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
  
Chemical Stability, Flammability, Ionization, Solubility
  
Electron Configuration
[Kr] 5s1
  
[Ar] 4s2
  
Crystal Structure
Body Centered Cubic (BCC)
  
Face Centered Cubic (FCC)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
FCC-Crystal-Structure-of-Calcium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
55.90 cm3/mol
  
2
29.90 cm3/mol
  
7
Adjacent Atomic Numbers
  
  
Valence Electron Potential
9.47 (-eV)
  
99+
29.00 (-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+
1.55 g/cm3
  
99+
Density When Liquid (at m.p.)
1.46 g/cm3
  
99+
1.38 g/cm3
  
99+
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Diamagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
128.00 nΩ·m
  
26
33.60 nΩ·m
  
99+
Electrical Conductivity
0.08 106/cm Ω
  
24
0.30 106/cm Ω
  
6
Electron Affinity
46.90 kJ/mol
  
24
2.37 kJ/mol
  
39
Specific Heat
0.36 J/(kg K)
  
17
0.63 J/(kg K)
  
7
Molar Heat Capacity
31.06 J/mol·K
  
5
25.93 J/mol·K
  
34
Thermal Conductivity
58.20 W/m·K
  
26
201.00 W/m·K
  
5
Critical Temperature
Not Available
  
Thermal Expansion
90.00 µm/(m·K)
  
2
22.30 µm/(m·K)
  
19
Enthalpy
  
  
Enthalpy of Vaporization
69.20 kJ/mol
  
99+
150.00 kJ/mol
  
99+
Enthalpy of Fusion
2.19 kJ/mol
  
99+
8.54 kJ/mol
  
99+
Enthalpy of Atomization
82.00 kJ/mol
  
99+
184.00 kJ/mol
  
99+
Standard Molar Entropy
76.80 J/mol.K
  
5
41.60 J/mol.K
  
36