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Cerium vs Protactinium


Protactinium vs Cerium


Periodic Table

Symbol
Ce   
Pa   

Group Number
Not Available   
Not Available   

Period Number
6   
7   

Block
f block   
f block   

Element Family
Lanthanide   
Actinide   

CAS Number
7440451   
99+
7440133   
99+

Space Group Name
P63/mmc   
I4/mmm   

Space Group Number
194.00   
5
139.00   
8

Facts

Interesting Facts
  • Cerium is a rare earth metal but still it is not rare at all.
  • It’s non-toxic compound Cerium sulfide has a rich red color and it is used as a pigment.
  • Cerium metal is also used in Flat screen TVs, light bulb, floodlights, etc.
  
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  

Sources
Found in Minerals, Mining, Ores of Minerals   
Found in Uranium Ores, Mining, Ores of metals   

History
  
  

Who Discovered
Martin Heinrich Klaproth, Jöns Jakob Berzelius, Wilhelm Hisinger   
William Crookes   

Discovery
In 1803   
In 1900   

Abundance
  
  

Abundance In Universe
1 * 10-6 %   
16
Not Available   

Abundance In Sun
~0.0000004 %   
23
~-9999 %   

Abundance In Meteorites
0.00 %   
27
Not Available   

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

Abundance In Oceans
0.00 %   
33
0.00 %   
99+

Uses

Uses & Benefits
  • It is used to include flints for cigarette lighters.
  • Its compound Cerium (Ill) Oxide is used as a catalyst; it is put inside the walls of the oven as it prevents from the buildup of cooking residues.
  
  • Currently known uses of Protactinium metal are limited to research purpose only.
  

Industrial Uses
Chemical Industry   
NA   

Medical Uses
Medical Research   
NA   

Other Uses
Alloys   
NA   

Biological Properties
  
  

Toxicity
Moderately Toxic   
Highly Toxic   

Present in Human Body
Yes   
No   

In Blood
0.00 Blood/mg dm-3   
30
0.00 Blood/mg dm-3   
37

In Bone
2.70 p.p.m.   
14
0.00 p.p.m.   
36

Physical Properties

Melting Point
795.00 °C   
99+
1,568.00 °C   
21

Boiling Point
3,257.00 °C   
23
4,027.00 °C   
12

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Silver   

Luster
Lustrous   
Metallic   

Hardness
  
  

Mohs Hardness
2.50   
14
Not Available   

Brinell Hardness
186.00 MPa   
99+
Not Available   

Vickers Hardness
210.00 MPa   
32
Not Available   

Speed of Sound
2,100.00 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
Ce   
Pa   

Isotopes
  
  

Known Isotopes
30   
9
27   
12

Electronegativity
  
  

Pauling Electronegativity
1.12   
99+
1.50   
27

Allred Rochow Electronegativity
1.08   
31
1.14   
28

Electropositivity
  
  

Pauling Electropositivity
2.88   
11
2.50   
27

Ionization Energies
  
  

1st Energy Level
534.40 kJ/mol   
99+
568.00 kJ/mol   
99+

2nd Energy Level
1,050.00 kJ/mol   
99+
1,128.00 kJ/mol   
99+

3rd Energy Level
1,949.00 kJ/mol   
99+
1,814.00 kJ/mol   
99+

4th Energy Level
3,547.00 kJ/mol   
99+
2,991.00 kJ/mol   
99+

5th Energy Level
6,325.00 kJ/mol   
22
Not Available   

6th Energy Level
7,490.00 kJ/mol   
21
Not Available   

Electrochemical Equivalent
1.74 g/amp-hr   
99+
1.72 g/amp-hr   
99+

Electron Work Function
2.84 eV   
39
Not Available   

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

Atomic Properties

Atomic Number
58   
99+
91   
27

Electron Configuration
[Xe] 4f1 5d1 6s2   
[Rn] 5f2 6d1 7s2   

Crystal Structure
Double Hexagonal Close Packed (DHCP)   
Tetragonal (TETR)   

Crystal Lattice
DHCP-Crystal-Structure-of-Cerium.jpg#100   
TETR-Crystal-Structure-of-Protactinium.jpg#100   

Atom
  
  

Number of Protons
58   
99+
91   
27

Number of Neutrons
82   
99+
122   
21

Number of Electrons
58   
99+
91   
27

Radius of an Atom
  
  

Atomic Radius
181.80 pm   
12
163.00 pm   
25

Covalent Radius
204.00 pm   
8
200.00 pm   
11

Van der Waals Radius
235.00 pm   
17
243.00 pm   
11

Atomic Weight
140.12 amu   
99+
231.04 amu   
24

Atomic Volume
20.67 cm3/mol   
17
15.00 cm3/mol   
34

Adjacent Atomic Numbers
  
  

Previous Element
Lanthanum
  
Thorium
  

Next Element
Uranium
  

Valence Electron Potential
41.78 (-eV)   
99+
92.00 (-eV)   
11

Lattice Constant
362.00 pm   
34
392.50 pm   
23

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

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
6.77 g/cm3   
99+
15.37 g/cm3   
20

Density When Liquid (at m.p.)
6.55 g/cm3   
38
Not Available   

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)   
34
Not Available   

Vapor Pressure at 2000 K
1.04 (Pa)   
13
Not Available   

Elasticity properties
  
  

Shear Modulus
13.50 GPa   
99+
Not Available   

Bulk Modulus
21.50 GPa   
99+
Not Available   

Young's Modulus
33.60 GPa   
99+
Not Available   

Poisson Ratio
0.24   
27
Not Available   

Other Mechanical Properties
Ductile, Malleable   
Unknown   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
6.77   
99+
15.37   
12

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
828.00 nΩ·m   
3
177.00 nΩ·m   
21

Electrical Conductivity
0.01 106/cm Ω   
99+
0.05 106/cm Ω   
34

Electron Affinity
50.00 kJ/mol   
21
Not Available   

Thermal Properties

Specific Heat
0.19 J/(kg K)   
32
0.12 J/(kg K)   
40

Molar Heat Capacity
26.94 J/mol·K   
23
Not Available   

Thermal Conductivity
11.30 W/m·K   
99+
47.00 W/m·K   
32

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
6.30 µm/(m·K)   
99+
9.90 µm/(m·K)   
40

Enthalpy
  
  

Enthalpy of Vaporization
414.00 kJ/mol   
16
Not Available   

Enthalpy of Fusion
5.46 kJ/mol   
99+
12.34 kJ/mol   
28

Enthalpy of Atomization
381.00 kJ/mol   
23
Not Available   

Standard Molar Entropy
72.00 J/mol.K   
12
198.10 J/mol.K   
1

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