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Protactinium Lanthanum Comparison


Lanthanum Protactinium comparison


Periodic Table

Symbol
Pa   
La   

Group Number
Not Available   
Not Available   

Period Number
7   
6   

Block
f block   
f block   

Element Family
Actinide   
Lanthanide   

CAS Number
7440133   
99+
7439910   
99+

Space Group Name
I4/mmm   
P63/mmc   

Space Group Number
139.00   
8
194.00   
5

Facts

Interesting Facts
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  
  • Lanthanum metal is highly malleable, ductile and sectile.
  • If exposed to air Lanthanum metal oxidizes rapidly.
  

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

History
  
  

Who Discovered
William Crookes   
Carl Gustaf Mosander   

Discovery
In 1900   
In 1838   

Abundance
  
  

Abundance In Universe
Not Available   
2 * 10-7 %   
22

Abundance In Sun
~-9999 %   
~0.0000002 %   
25

Abundance In Meteorites
Not Available   
0.00 %   
32

Abundance In Earth's Crust
0.00 %   
99+
0.00 %   
19

Abundance In Oceans
0.00 %   
99+
0.00 %   
29

Uses

Uses & Benefits
  • Currently known uses of Protactinium metal are limited to research purpose only.
  
  • It has no commercial uses, but its alloys are in high demand. Lanthanum and Nickel alloy is used for the hydrogen gas storage.
  • The best-known use for mischmetal alloy of Lanthanum is; as a ‘flints’ for cigarette lighters.
  

Industrial Uses
NA   
Electrical Industry, Electronic Industry   

Medical Uses
NA   
NA   

Other Uses
NA   
Alloys, Mirror Manufacturing   

Biological Properties
  
  

Toxicity
Highly Toxic   
Low Toxic   

Present in Human Body
No   
Yes   

In Blood
0.00 Blood/mg dm-3   
37
Not Available   

In Bone
0.00 p.p.m.   
36
0.08 p.p.m.   
24

Physical Properties

Melting Point
1,568.00 °C   
21
920.00 °C   
99+

Boiling Point
4,027.00 °C   
12
3,469.00 °C   
18

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silver   
Silvery White   

Luster
Metallic   
NA   

Hardness
  
  

Mohs Hardness
Not Available   
2.50   
14

Brinell Hardness
Not Available   
350.00 MPa   
30

Vickers Hardness
Not Available   
360.00 MPa   
26

Speed of Sound
Not Available   
2,475.00 m/s   
37

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
Pa   
La   

Isotopes
  
  

Known Isotopes
27   
12
31   
8

Electronegativity
  
  

Pauling Electronegativity
1.50   
27
1.10   
99+

Allred Rochow Electronegativity
1.14   
28
1.08   
31

Electropositivity
  
  

Pauling Electropositivity
2.50   
27
2.90   
10

Ionization Energies
  
  

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

2nd Energy Level
1,128.00 kJ/mol   
99+
1,067.00 kJ/mol   
99+

3rd Energy Level
1,814.00 kJ/mol   
99+
1,850.30 kJ/mol   
99+

4th Energy Level
2,991.00 kJ/mol   
99+
4,819.00 kJ/mol   
22

5th Energy Level
Not Available   
5,940.00 kJ/mol   
25

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

Electron Work Function
Not Available   
3.50 eV   
31

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

Atomic Properties

Atomic Number
91   
27
57   
99+

Electron Configuration
[Rn] 5f2 6d1 7s2   
[Xe] 5d2 6s2   

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

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

Atom
  
  

Number of Protons
91   
27
57   
99+

Number of Neutrons
122   
21
82   
99+

Number of Electrons
91   
27
57   
99+

Radius of an Atom
  
  

Atomic Radius
163.00 pm   
25
187.00 pm   
8

Covalent Radius
200.00 pm   
11
207.00 pm   
6

Van der Waals Radius
243.00 pm   
11
240.00 pm   
13

Atomic Weight
231.04 amu   
24
138.91 amu   
99+

Atomic Volume
15.00 cm3/mol   
34
20.73 cm3/mol   
16

Adjacent Atomic Numbers
  
  

Previous Element
Thorium
  
Barium
  

Next Element
Uranium
  
Cerium
  

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

Lattice Constant
392.50 pm   
23
377.20 pm   
28

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

Lattice C/A Ratio
Not Available   
1.62   
2

Mechanical Properties

Density
  
  

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

Density When Liquid (at m.p.)
Not Available   
5.94 g/cm3   
99+

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
Not Available   
0.98 (Pa)   
15

Elasticity properties
  
  

Shear Modulus
Not Available   
14.30 GPa   
40

Bulk Modulus
Not Available   
27.90 GPa   
99+

Young's Modulus
Not Available   
36.60 GPa   
99+

Poisson Ratio
Not Available   
0.28   
17

Other Mechanical Properties
Unknown   
Ductile   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
15.37   
12
6.17   
99+

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
177.00 nΩ·m   
21
615.00 nΩ·m   
7

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

Electron Affinity
Not Available   
48.00 kJ/mol   
23

Thermal Properties

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

Molar Heat Capacity
Not Available   
27.11 J/mol·K   
21

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
9.90 µm/(m·K)   
40
12.10 µm/(m·K)   
32

Enthalpy
  
  

Enthalpy of Vaporization
Not Available   
399.60 kJ/mol   
17

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

Enthalpy of Atomization
Not Available   
431.00 kJ/mol   
16

Standard Molar Entropy
198.10 J/mol.K   
1
56.90 J/mol.K   
23

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