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Americium Protactinium Comparison


Protactinium Americium comparison


Periodic Table

Symbol
Am   
Pa   

Group Number
Not Available   
Not Available   

Period Number
7   
7   

Block
f block   
f block   

Element Family
Actinide   
Actinide   

CAS Number
7440359   
99+
7440133   
99+

Space Group Name
P63/mmc   
I4/mmm   

Space Group Number
194.00   
5
139.00   
8

Facts

Interesting Facts
  • Americium metal is produced by bombarding Plutonium with Neutrons.
  • Americium metal was discovered as a by-product while testing an atomic bomb (Manhattan Project).
  
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  

Sources
Obtained By Bombarding Plutonium with Neutrons   
Found in Uranium Ores, Mining, Ores of metals   

History
  
  

Who Discovered
Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso   
William Crookes   

Discovery
In 1944   
In 1900   

Abundance
  
  

Abundance In Earth's Crust
Not Available   
0.00 %   
99+

Abundance In Oceans
Not Available   
0.00 %   
99+

Uses

Uses & Benefits
  • Americium metal is used in smoke detection alarms.
  • In the future, this metal has a potential to be used in batteries of spacecrafts.
  
  • Currently known uses of Protactinium metal are limited to research purpose only.
  

Industrial Uses
NA   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys, Nuclear Research, Research Purposes   
NA   

Biological Properties
  
  

Toxicity
Toxic   
Highly Toxic   

Present in Human Body
No   
No   

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

In Bone
0.00 p.p.m.   
36
0.00 p.p.m.   
36

Physical Properties

Melting Point
994.00 °C   
99+
1,568.00 °C   
21

Boiling Point
2,607.00 °C   
99+
4,027.00 °C   
12

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Silver   

Luster
NA   
Metallic   

Hardness
  
  

Speed of Sound
Not Available   
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
Am   
Pa   

Isotopes
  
  

Known Isotopes
16   
23
27   
12

Electronegativity
  
  

Pauling Electronegativity
1.30   
32
1.50   
27

Allred Rochow Electronegativity
1.20   
27
1.14   
28

Electropositivity
  
  

Pauling Electropositivity
2.70   
22
2.50   
27

Ionization Energies
  
  

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

2nd Energy Level
1,158.00 kJ/mol   
99+
1,128.00 kJ/mol   
99+

3rd Energy Level
2,132.00 kJ/mol   
99+
1,814.00 kJ/mol   
99+

4th Energy Level
3,493.00 kJ/mol   
99+
2,991.00 kJ/mol   
99+

Electrochemical Equivalent
3.02 g/amp-hr   
17
1.72 g/amp-hr   
99+

Electron Work Function
Not Available   
Not Available   

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

Atomic Properties

Atomic Number
95   
23
91   
27

Electron Configuration
[Rn] 5f7 7s2   
[Rn] 5f2 6d1 7s2   

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

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

Atom
  
  

Number of Protons
95   
23
91   
27

Number of Neutrons
148   
12
122   
21

Number of Electrons
95   
23
91   
27

Radius of an Atom
  
  

Atomic Radius
173.00 pm   
21
163.00 pm   
25

Covalent Radius
180.00 pm   
21
200.00 pm   
11

Van der Waals Radius
244.00 pm   
10
243.00 pm   
11

Atomic Weight
243.00 amu   
20
231.04 amu   
24

Atomic Volume
17.86 cm3/mol   
29
15.00 cm3/mol   
34

Adjacent Atomic Numbers
  
  

Previous Element
Plutonium
  
Thorium
  

Next Element
Curium
  
Uranium
  

Valence Electron Potential
44.00 (-eV)   
40
92.00 (-eV)   
11

Lattice Constant
346.81 pm   
99+
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
12.00 g/cm3   
30
15.37 g/cm3   
20

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)   
13
Not Available   

Elasticity properties
  
  

Poisson Ratio
Not Available   
Not Available   

Other Mechanical Properties
NA   
Unknown   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
13.67   
15
15.37   
12

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Unknown   
Conductor   

Resistivity
0.69 nΩ·m   
99+
177.00 nΩ·m   
21

Electrical Conductivity
0.02 106/cm Ω   
99+
0.05 106/cm Ω   
34

Thermal Properties

Specific Heat
0.11 J/(kg K)   
99+
0.12 J/(kg K)   
40

Molar Heat Capacity
62.70 J/mol·K   
1
Not Available   

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
Not Available   
9.90 µm/(m·K)   
40

Enthalpy
  
  

Enthalpy of Fusion
14.39 kJ/mol   
24
12.34 kJ/mol   
28

Enthalpy of Atomization
268.00 kJ/mol   
40
Not Available   

Standard Molar Entropy
Not Available   
198.10 J/mol.K   
1

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