Symbol
Cf
  
Pa
  
Group Number
Not Available
  
Not Available
  
Period Number
7
  
7
  
Block
f block
  
f block
  
Element Family
Actinide
  
Actinide
  
Space Group Name
P63/mmc
  
I4/mmm
  
Interesting Facts
- Californium metal is very harmful and highly radioactive.
- Californium metal is the heaviest metal.
  
- Protactinium metal has 29 isotopes.
- Isotopes of Protactinium-231 used in nuclear weapon.
  
Sources
Made by Bombarding Curium with Helium Ions
  
Found in Uranium Ores, Mining, Ores of metals
  
History
  
  
Who Discovered
Lawrence Berkeley National Laboratory
  
William Crookes
  
Discovery
In 1950
  
In 1900
  
Abundance
  
  
Abundance In Earth's Crust
Not Available
  
Abundance In Oceans
Not Available
  
Uses & Benefits
- Californium metal has a very strong neutron emitter. It is used as a metal detector.
-
It also used as an identifier to check Water and oil layers in oil wells.
  
- Currently known uses of Protactinium metal are limited to research purpose only.
  
Industrial Uses
Chemical Industry
  
NA
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys, Nuclear Research
  
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
Melting Point
1,568.00 °C
  
21
Boiling Point
1,470.00 °C
  
99+
4,027.00 °C
  
12
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Silver
  
Luster
NA
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
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
Cf
  
Pa
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
608.00 kJ/mol
  
99+
568.00 kJ/mol
  
99+
2nd Energy Level
1,206.00 kJ/mol
  
99+
1,128.00 kJ/mol
  
99+
3rd Energy Level
2,267.00 kJ/mol
  
99+
1,814.00 kJ/mol
  
99+
4th Energy Level
3,599.00 kJ/mol
  
99+
2,991.00 kJ/mol
  
99+
Electrochemical Equivalent
3.12 g/amp-hr
  
15
1.72 g/amp-hr
  
99+
Electron Work Function
Not Available
  
Not Available
  
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity, Solubility
  
Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Rn] 5f10 7s2
  
[Rn] 5f2 6d1 7s2
  
Crystal Structure
Double Hexagonal Close Packed (DHCP)
  
Tetragonal (TETR)
  
Crystal Lattice
DHCP-Crystal-Structure-of-Californium.jpg#100
  
TETR-Crystal-Structure-of-Protactinium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Covalent Radius
Not Available
  
Van der Waals Radius
Not Available
  
Atomic Volume
Not Available
  
15.00 cm3/mol
  
34
Adjacent Atomic Numbers
  
  
Valence Electron Potential
44.50 (-eV)
  
38
92.00 (-eV)
  
11
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
15.10 g/cm3
  
21
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
Malleable, Sectile
  
Unknown
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Unknown
  
Conductor
  
Resistivity
Not Available
  
177.00 nΩ·m
  
21
Electrical Conductivity
Not Available
  
0.05 10
6/cm Ω
  
34
Specific Heat
Not Available
  
0.12 J/(kg K)
  
40
Molar Heat Capacity
Not Available
  
Not Available
  
Thermal Conductivity
Not Available
  
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
Standard Molar Entropy
Not Available
  
198.10 J/mol.K
  
1