Symbol
Pa
  
Mo
  
Group Number
Not Available
  
Period Number
7
  
5
  
Block
f block
  
d block
  
Element Family
Actinide
  
Transition Metal
  
Space Group Name
I4/mmm
  
Im_ 3m
  
Interesting Facts
- Protactinium metal has 29 isotopes.
- Isotopes of Protactinium-231 used in nuclear weapon.
  
- Molybdenum is highly reactive metal, hence not found free in nature .
- Till 18th century Molybdenum element were often mistaken as a carbon or Lead.
  
Sources
Found in Uranium Ores, Mining, Ores of metals
  
Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
William Crookes
  
Carl Wilhelm Scheele
  
Discovery
In 1900
  
In 1778
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~-9999 %
  
~0.0000009 %
  
19
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Abundance In Humans
Not Available
  
Uses & Benefits
- Currently known uses of Protactinium metal are limited to research purpose only.
  
- Its alloys are used to make engine parts, drills, saw blade, etc.
- Lubricant additive made up of Molybdenum disulfide is commonly used in the industry. It is also used as a catalyst.
  
Industrial Uses
NA
  
Aerospace Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
NA
  
Other Uses
NA
  
Alloys
  
Biological Properties
  
  
Toxicity
Highly Toxic
  
Toxic
  
Present in Human Body
No
  
Yes
  
In Blood
0.00 Blood/mg dm-3
  
37
0.00 Blood/mg dm-3
  
31
In Bone
0.00 p.p.m.
  
36
0.70 p.p.m.
  
18
Melting Point
1,568.00 °C
  
21
Boiling Point
4,027.00 °C
  
12
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Gray
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
1,370.00 MPa
  
7
Vickers Hardness
Not Available
  
1,400.00 MPa
  
6
Speed of Sound
Not Available
  
5,400.00 m/s
  
6
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Pa
  
Mo
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
568.00 kJ/mol
  
99+
684.30 kJ/mol
  
37
2nd Energy Level
1,128.00 kJ/mol
  
99+
1,560.00 kJ/mol
  
37
3rd Energy Level
1,814.00 kJ/mol
  
99+
2,618.00 kJ/mol
  
99+
4th Energy Level
2,991.00 kJ/mol
  
99+
4,480.00 kJ/mol
  
26
5th Energy Level
Not Available
  
5,257.00 kJ/mol
  
32
6th Energy Level
Not Available
  
6,640.80 kJ/mol
  
22
7th Energy level
Not Available
  
12,125.00 kJ/mol
  
13
8th Energy Level
Not Available
  
13,860.00 kJ/mol
  
16
9th Energy Level
Not Available
  
15,835.00 kJ/mol
  
16
10th Energy Level
Not Available
  
17,980.00 kJ/mol
  
18
11th Energy Level
Not Available
  
20,190.00 kJ/mol
  
17
12th Energy Level
Not Available
  
22,219.00 kJ/mol
  
15
13th Energy Level
Not Available
  
26,930.00 kJ/mol
  
13
14th Energy Level
Not Available
  
29,196.00 kJ/mol
  
13
15th Energy Level
Not Available
  
52,490.00 kJ/mol
  
7
16th Energy Level
Not Available
  
55,000.00 kJ/mol
  
8
17th Energy Level
Not Available
  
61,400.00 kJ/mol
  
9
18th Energy Level
Not Available
  
67,700.00 kJ/mol
  
9
19th Energy Level
Not Available
  
74,000.00 kJ/mol
  
9
20th Energy Level
Not Available
  
80,400.00 kJ/mol
  
10
21st Energy Level
Not Available
  
87,000.00 kJ/mol
  
9
22nd Energy Level
Not Available
  
93,400.00 kJ/mol
  
7
23rd Energy Level
Not Available
  
98,420.00 kJ/mol
  
6
24th Energy Level
Not Available
  
104,400.00 kJ/mol
  
2
25th Energy Level
Not Available
  
121,900.00 kJ/mol
  
1
26th Energy Level
Not Available
  
127,700.00 kJ/mol
  
1
27th Energy Level
Not Available
  
133,800.00 kJ/mol
  
1
28th Energy Level
Not Available
  
139,800.00 kJ/mol
  
1
29th Energy Level
Not Available
  
148,100.00 kJ/mol
  
1
30th Energy Level
Not Available
  
154,500.00 kJ/mol
  
1
Electrochemical Equivalent
1.72 g/amp-hr
  
99+
0.89 g/amp-hr
  
99+
Electron Work Function
Not Available
  
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity
  
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Rn] 5f2 6d1 7s2
  
[Kr] 4d5 5s1
  
Crystal Structure
Tetragonal (TETR)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
15.00 cm3/mol
  
34
9.40 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
92.00 (-eV)
  
11
88.60 (-eV)
  
13
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
15.37 g/cm3
  
20
10.28 g/cm3
  
36
Density When Liquid (at m.p.)
Not Available
  
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Unknown
  
Ductile, Weldable
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Semiconductor
  
Resistivity
177.00 nΩ·m
  
21
53.40 nΩ·m
  
99+
Electrical Conductivity
0.05 106/cm Ω
  
34
0.19 106/cm Ω
  
11
Electron Affinity
Not Available
  
71.90 kJ/mol
  
14
Specific Heat
0.12 J/(kg K)
  
40
0.25 J/(kg K)
  
21
Molar Heat Capacity
Not Available
  
24.06 J/mol·K
  
99+
Thermal Conductivity
47.00 W/m·K
  
32
138.00 W/m·K
  
12
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
9.90 µm/(m·K)
  
40
4.80 µm/(m·K)
  
99+
Enthalpy
  
  
Enthalpy of Vaporization
Not Available
  
594.10 kJ/mol
  
8
Enthalpy of Fusion
12.34 kJ/mol
  
28
27.61 kJ/mol
  
5
Enthalpy of Atomization
Not Available
  
653.00 kJ/mol
  
7
Standard Molar Entropy
198.10 J/mol.K
  
1
28.70 J/mol.K
  
99+