Symbol
Ra
  
Pa
  
Group Number
Not Available
  
Period Number
7
  
7
  
Block
s block
  
f block
  
Element Family
Alkaline Earth
  
Actinide
  
Space Group Name
Im_ 3m
  
I4/mmm
  
Interesting Facts
- Radium metal is the heaviest metal of Alkaline earth metals column.
- Radium metal is highly radioactive and does not have any stable isotopes.
  
- Protactinium metal has 29 isotopes.
- Isotopes of Protactinium-231 used in nuclear weapon.
  
Sources
Mining, Ores of metals
  
Found in Uranium Ores, Mining, Ores of metals
  
History
  
  
Who Discovered
Not Available
  
William Crookes
  
Discovery
In 1898
  
In 1900
  
Abundance
  
  
Abundance In Earth's Crust
Abundance In Humans
Not Available
  
Uses & Benefits
- It is a highly radioactive metal; and sometime Radium-223 is used to treat prostate cancer.
-
It is used in luminous paints.
  
- Currently known uses of Protactinium metal are limited to research purpose only.
  
Industrial Uses
NA
  
NA
  
Medical Uses
Pharmaceutical Industry
  
NA
  
Other Uses
NA
  
NA
  
Biological Properties
  
  
Toxicity
Highly Toxic
  
Highly Toxic
  
Present in Human Body
No
  
No
  
In Blood
Not Available
  
0.00 Blood/mg dm-3
  
37
In Bone
Not Available
  
0.00 p.p.m.
  
36
Melting Point
1,568.00 °C
  
21
Boiling Point
1,737.00 °C
  
99+
4,027.00 °C
  
12
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Silver
  
Luster
Metallic
  
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 Formula
Ra
  
Pa
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
509.30 kJ/mol
  
99+
568.00 kJ/mol
  
99+
2nd Energy Level
979.00 kJ/mol
  
99+
1,128.00 kJ/mol
  
99+
3rd Energy Level
Not Available
  
1,814.00 kJ/mol
  
99+
4th Energy Level
Not Available
  
2,991.00 kJ/mol
  
99+
Electrochemical Equivalent
4.22 g/amp-hr
  
6
1.72 g/amp-hr
  
99+
Electron Work Function
Not Available
  
Not Available
  
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity
  
Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Rn] 7s2
  
[Rn] 5f2 6d1 7s2
  
Crystal Structure
Body Centered Cubic (BCC)
  
Tetragonal (TETR)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
TETR-Crystal-Structure-of-Protactinium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Radius
Not Available
  
Atomic Volume
45.20 cm3/mol
  
4
15.00 cm3/mol
  
34
Adjacent Atomic Numbers
  
  
Valence Electron Potential
20.10 (-eV)
  
99+
92.00 (-eV)
  
11
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
5.50 g/cm3
  
99+
15.37 g/cm3
  
20
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Poisson Ratio
Not Available
  
Not Available
  
Other Mechanical Properties
NA
  
Unknown
  
Magnetic Characteristics
  
  
Magnetic Ordering
Nonmagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
NA
  
Conductor
  
Resistivity
100.00 nΩ·m
  
31
177.00 nΩ·m
  
21
Electrical Conductivity
Not Available
  
0.05 10
6/cm Ω
  
34
Specific Heat
0.12 J/(kg K)
  
40
0.12 J/(kg K)
  
40
Molar Heat Capacity
Not Available
  
Not Available
  
Thermal Conductivity
18.60 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
Not Available
  
12.34 kJ/mol
  
28
Enthalpy of Atomization
163.00 kJ/mol
  
99+
Not Available
  
Standard Molar Entropy
71.00 J/mol.K
  
14
198.10 J/mol.K
  
1