Symbol
Pa
  
Po
  
Group Number
Not Available
  
Period Number
7
  
6
  
Block
f block
  
p block
  
Element Family
Actinide
  
Post-Transition
  
Space Group Name
I4/mmm
  
Pm-3m
  
Interesting Facts
- Protactinium metal has 29 isotopes.
- Isotopes of Protactinium-231 used in nuclear weapon.
  
- Polonium was the first radioactive element to be discovered.
- Polonium element and its compounds are highly radioactive.
- Its alloy with Beryllium provides source of neutrons.
  
Sources
Found in Uranium Ores, Mining, Ores of metals
  
Mining, Ores of metals
  
History
  
  
Who Discovered
William Crookes
  
Pierre Curie and Marie Curie
  
Discovery
In 1900
  
In 1898
  
Abundance
  
  
Abundance In Earth's Crust
Not Available
  
Uses & Benefits
- Currently known uses of Protactinium metal are limited to research purpose only.
  
- Polonium metal has different Allotropes, it is used in antistatic devices and for research purpose.
- A 1 gram of Polonium can reach a temperature of 500°C, hence it is used as a heat source for space equipment.
  
Industrial Uses
NA
  
Aerospace Industry, Ammunition Industry
  
Medical Uses
NA
  
NA
  
Other Uses
NA
  
Alloys
  
Biological Properties
  
  
Toxicity
Highly 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
Melting Point
1,568.00 °C
  
21
Boiling Point
4,027.00 °C
  
12
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Silver
  
Luster
Metallic
  
NA
  
Hardness
  
  
Speed of Sound
Not Available
  
Not Available
  
Optical Properties
  
  
Allotropes
No
  
Yes
  
α Allotropes
Not Available
  
α-polonium
  
β Allotropes
Not Available
  
β-polonium
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Pa
  
Po
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
568.00 kJ/mol
  
99+
812.10 kJ/mol
  
14
2nd Energy Level
1,128.00 kJ/mol
  
99+
Not Available
  
3rd Energy Level
1,814.00 kJ/mol
  
99+
Not Available
  
4th Energy Level
2,991.00 kJ/mol
  
99+
Not Available
  
Electrochemical Equivalent
1.72 g/amp-hr
  
99+
3.90 g/amp-hr
  
8
Electron Work Function
Not Available
  
Not Available
  
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity
  
Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Rn] 5f2 6d1 7s2
  
[Xe] 4f14 5d10 6s2 6p4
  
Crystal Structure
Tetragonal (TETR)
  
Monoclinic (MON)
  
Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100
  
MON-Crystal-Structure-of-Polonium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
15.00 cm3/mol
  
34
22.23 cm3/mol
  
13
Adjacent Atomic Numbers
  
  
Valence Electron Potential
92.00 (-eV)
  
11
Not Available
  
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
9.20 g/cm3
  
99+
Density When Liquid (at m.p.)
Not Available
  
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Poisson Ratio
Not Available
  
Not Available
  
Other Mechanical Properties
Unknown
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Nonmagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
177.00 nΩ·m
  
21
Electrical Conductivity
0.05 106/cm Ω
  
34
0.02 106/cm Ω
  
99+
Electron Affinity
Not Available
  
183.30 kJ/mol
  
3
Specific Heat
0.12 J/(kg K)
  
40
0.12 J/(kg K)
  
40
Molar Heat Capacity
Not Available
  
26.40 J/mol·K
  
28
Thermal Conductivity
47.00 W/m·K
  
32
20.00 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
9.90 µm/(m·K)
  
40
23.50 µm/(m·K)
  
16
Enthalpy
  
  
Enthalpy of Vaporization
Not Available
  
60.30 kJ/mol
  
99+
Enthalpy of Fusion
12.34 kJ/mol
  
28
13.00 kJ/mol
  
26
Enthalpy of Atomization
Not Available
  
134.00 kJ/mol
  
99+
Standard Molar Entropy
198.10 J/mol.K
  
1
Not Available