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Hafnium Rubidium Comparison


Rubidium Hafnium comparison


Periodic Table

Symbol
Hf   
Rb   

Group Number
4   
14
1   
17

Period Number
6   
5   

Block
d block   
s block   

Element Family
Transition Metal   
Alkali   

CAS Number
7440586   
30
7440177   
99+

Space Group Name
P63/mmc   
Im_ 3m   

Space Group Number
194.00   
5
229.00   
1

Facts

Interesting Facts
  • Hafnium metal is highly reactive, hence not found free in nature.
  • Hafnium metal as predicated after Mendeleev finished his periodic table.
  
  • Rubidium metal is 16th most common element found in the earth crust.
  • Rubidium metal also found in minerals as well as seawater.
  

Sources
By-product Zirconium Refining   
Obtained from Lithium Production.   

History
  
  

Who Discovered
Dirk Coster and George de Hevesy   
Robert Bunsen and Gustav Kirchhoff   

Discovery
In 1922   
In 1861   

Abundance
  
  

Abundance In Universe
7 * 10-8 %   
25
1 * 10-6 %   
16

Abundance In Sun
~0.0000001 %   
26
~0.000003 %   
17

Abundance In Meteorites
0.00 %   
37
0.00 %   
19

Abundance In Earth's Crust
0.00 %   
31
0.01 %   
18

Abundance In Oceans
0.00 %   
27
0.00 %   
7

Abundance In Humans
Not Available   
0.00 %   
7

Uses

Uses & Benefits
  • It has an ability to absorb neutrons and hence it is used to make control rods in nuclear submarines. And this metal is also used in Plasma welding torches.
  • It alloys with iron, titanium and niobium are very useful.
  
  • 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
Ammunition Industry   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes   
Alloys, Research Purposes   

Biological Properties
  
  

Toxicity
Toxic   
Non Toxic   

Present in Human Body
No   
Yes   

In Blood
Not Available   
2.49 Blood/mg dm-3   
7

In Bone
Not Available   
5.00 p.p.m.   
13

Physical Properties

Melting Point
2,150.00 °C   
10
38.89 °C   
99+

Boiling Point
5,400.00 °C   
5
688.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
Gray   
Grayish White   

Luster
Metallic   
NA   

Hardness
  
  

Mohs Hardness
5.50   
7
0.30   
24

Brinell Hardness
1,450.00 MPa   
6
0.22 MPa   
99+

Vickers Hardness
1,520.00 MPa   
5
Not Available   

Speed of Sound
3,010.00 m/s   
27
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
Hf   
Rb   

Isotopes
  
  

Known Isotopes
32   
7
29   
10

Electronegativity
  
  

Pauling Electronegativity
1.30   
32
0.82   
99+

Sanderson Electronegativity
Not Available   
0.31   
32

Allred Rochow Electronegativity
1.23   
25
0.89   
40

Mulliken-Jaffe Electronegativity
Not Available   
0.69   
24

Allen Electronegativity
1.16   
37
0.71   
99+

Electropositivity
  
  

Pauling Electropositivity
2.70   
22
3.18   
3

Ionization Energies
  
  

1st Energy Level
658.50 kJ/mol   
40
403.00 kJ/mol   
99+

2nd Energy Level
1,440.00 kJ/mol   
99+
2,633.00 kJ/mol   
6

3rd Energy Level
2,250.00 kJ/mol   
99+
3,860.00 kJ/mol   
11

4th Energy Level
3,216.00 kJ/mol   
99+
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
1.66 g/amp-hr   
99+
3.19 g/amp-hr   
14

Electron Work Function
3.90 eV   
27
2.16 eV   
99+

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

Atomic Properties

Atomic Number
72   
99+
37   
99+

Electron Configuration
[Xe] 4f14 5d2 6s2   
[Kr] 5s1   

Crystal Structure
Hexagonal Close Packed (HCP)   
Body Centered Cubic (BCC)   

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

Atom
  
  

Number of Protons
72   
99+
37   
99+

Number of Neutrons
106   
29
48   
99+

Number of Electrons
72   
99+
37   
99+

Radius of an Atom
  
  

Atomic Radius
159.00 pm   
28
248.00 pm   
2

Covalent Radius
175.00 pm   
23
220.00 pm   
4

Van der Waals Radius
200.00 pm   
28
303.00 pm   
3

Atomic Weight
178.49 amu   
39
85.47 amu   
99+

Atomic Volume
13.60 cm3/mol   
38
55.90 cm3/mol   
2

Adjacent Atomic Numbers
  
  

Previous Element
Lutetium
  
Gallium
  

Next Element
Tantalum
  
Strontium
  

Valence Electron Potential
81.00 (-eV)   
16
9.47 (-eV)   
99+

Lattice Constant
319.64 pm   
99+
558.50 pm   
10

Lattice Angles
π/2, π/2, 2 π/3   
π/2, π/2, π/2   

Lattice C/A Ratio
1.58   
12
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
13.31 g/cm3   
26
1.53 g/cm3   
99+

Density When Liquid (at m.p.)
12.00 g/cm3   
12
1.46 g/cm3   
99+

Tensile Strength
445.00 MPa   
8
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
0.00 (Pa)   
24
Not Available   

Elasticity properties
  
  

Shear Modulus
30.00 GPa   
23
Not Available   

Bulk Modulus
110.00 GPa   
15
2.50 GPa   
99+

Young's Modulus
78.00 GPa   
25
2.40 GPa   
99+

Poisson Ratio
0.37   
7
Not Available   

Other Mechanical Properties
Ductile, Malleable   
Ductile   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
13.31   
18
1.53   
99+

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
331.00 nΩ·m   
14
128.00 nΩ·m   
26

Electrical Conductivity
0.03 106/cm Ω   
39
0.08 106/cm Ω   
24

Electron Affinity
0.00 kJ/mol   
40
46.90 kJ/mol   
24

Thermal Properties

Specific Heat
0.14 J/(kg K)   
37
0.36 J/(kg K)   
17

Molar Heat Capacity
25.73 J/mol·K   
36
31.06 J/mol·K   
5

Thermal Conductivity
23.00 W/m·K   
99+
58.20 W/m·K   
26

Critical Temperature
Not Available   
2,093.00 K   
4

Thermal Expansion
5.90 µm/(m·K)   
99+
90.00 µm/(m·K)   
2

Enthalpy
  
  

Enthalpy of Vaporization
661.10 kJ/mol   
5
69.20 kJ/mol   
99+

Enthalpy of Fusion
25.10 kJ/mol   
8
2.19 kJ/mol   
99+

Enthalpy of Atomization
703.00 kJ/mol   
5
82.00 kJ/mol   
99+

Standard Molar Entropy
43.60 J/mol.K   
34
76.80 J/mol.K   
5

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