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Rubidium Radium Comparison


Radium Rubidium comparison


Periodic Table

Symbol
Rb   
Ra   

Group Number
1   
17
2   
16

Period Number
5   
7   

Block
s block   
s block   

Element Family
Alkali   
Alkaline Earth   

CAS Number
7440177   
99+
7440144   
99+

Space Group Name
Im_ 3m   
Im_ 3m   

Space Group Number
229.00   
1
229.00   
1

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.
  
  • 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
1 * 10-6 %   
16
Not Available   

Abundance In Sun
~0.000003 %   
17
~-9999 %   

Abundance In Meteorites
0.00 %   
19
Not Available   

Abundance In Earth's Crust
0.01 %   
18
0.00 %   
99+

Abundance In Oceans
0.00 %   
7
0.00 %   
99+

Abundance In Humans
0.00 %   
7
0.00 %   
20

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.
  
  • 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   

Physical Properties

Melting Point
38.89 °C   
99+
700.00 °C   
99+

Boiling Point
688.00 °C   
99+
1,737.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
Grayish White   
Silvery White   

Luster
NA   
Metallic   

Hardness
  
  

Mohs Hardness
0.30   
24
Not Available   

Brinell Hardness
0.22 MPa   
99+
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 Properties

Chemical Formula
Rb   
Ra   

Isotopes
  
  

Known Isotopes
29   
10
33   
6

Electronegativity
  
  

Pauling Electronegativity
0.82   
99+
0.90   
99+

Sanderson Electronegativity
0.31   
32
Not Available   

Allred Rochow Electronegativity
0.89   
40
0.97   
38

Mulliken-Jaffe Electronegativity
0.69   
24
0.92   
20

Allen Electronegativity
0.71   
99+
0.89   
99+

Electropositivity
  
  

Pauling Electropositivity
3.18   
3
3.10   
5

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
2.16 eV   
99+
Not Available   

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

Atomic Properties

Atomic Number
37   
99+
88   
30

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
  
  

Number of Protons
37   
99+
88   
30

Number of Neutrons
48   
99+
138   
16

Number of Electrons
37   
99+
88   
30

Radius of an Atom
  
  

Atomic Radius
248.00 pm   
2
Not Available   

Covalent Radius
220.00 pm   
4
221.00 pm   
3

Van der Waals Radius
303.00 pm   
3
283.00 pm   
4

Atomic Weight
85.47 amu   
99+
226.00 amu   
26

Atomic Volume
55.90 cm3/mol   
2
45.20 cm3/mol   
4

Adjacent Atomic Numbers
  
  

Previous Element
Gallium
  
Francium
  

Next Element
Strontium
  
Actinium
  

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

Lattice Constant
558.50 pm   
10
514.80 pm   
13

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
1.53 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
2.50 GPa   
99+
Not Available   

Young's Modulus
2.40 GPa   
99+
Not Available   

Poisson Ratio
Not Available   
Not Available   

Other Mechanical Properties
Ductile   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
1.53   
99+
5.00   
99+

Magnetic Ordering
Paramagnetic   
Nonmagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
NA   

Resistivity
128.00 nΩ·m   
26
100.00 nΩ·m   
31

Electrical Conductivity
0.08 106/cm Ω   
24
Not Available   

Electron Affinity
46.90 kJ/mol   
24
Not Available   

Thermal Properties

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
2,093.00 K   
4
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

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