Symbol
Pa
  
Yb
  
Group Number
Not Available
  
Not Available
  
Period Number
7
  
6
  
Block
f block
  
f block
  
Element Family
Actinide
  
Lanthanide
  
Space Group Name
I4/mmm
  
Fm_ 3m
  
Interesting Facts
- Protactinium metal has 29 isotopes.
- Isotopes of Protactinium-231 used in nuclear weapon.
  
- Ytterbium metal oxidizes rapidly if exposed to air.
- Ytterbium metal can dissolve quickly in Mineral acid.
  
Sources
Found in Uranium Ores, Mining, Ores of metals
  
Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
William Crookes
  
Jean Charles Galissard de Marignac
  
Discovery
In 1900
  
In 1878
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~-9999 %
  
~0.0000001 %
  
26
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Uses & Benefits
- Currently known uses of Protactinium metal are limited to research purpose only.
  
- Ytterbium metal is used in memory devices and tuneable laser.
-
It is also used as industrial catalyst as the other catalysts are too toxic and polluting.
  
Industrial Uses
NA
  
Automobile Industry, Chemical 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
Not Available
  
In Bone
0.00 p.p.m.
  
36
Not Available
  
Melting Point
1,568.00 °C
  
21
Boiling Point
4,027.00 °C
  
12
1,196.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Silvery White
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Brinell Hardness
Not Available
  
Vickers Hardness
Not Available
  
Speed of Sound
Not Available
  
1,590.00 m/s
  
99+
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
Pa
  
Yb
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Not Available
  
Allred Rochow Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Not Available
  
Ionization Energies
  
  
1st Energy Level
568.00 kJ/mol
  
99+
603.40 kJ/mol
  
99+
2nd Energy Level
1,128.00 kJ/mol
  
99+
1,174.80 kJ/mol
  
99+
3rd Energy Level
1,814.00 kJ/mol
  
99+
2,417.00 kJ/mol
  
99+
4th Energy Level
2,991.00 kJ/mol
  
99+
4,203.00 kJ/mol
  
31
Electrochemical Equivalent
1.72 g/amp-hr
  
99+
2.15 g/amp-hr
  
25
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 6s2
  
Crystal Structure
Tetragonal (TETR)
  
Face Centered Cubic (FCC)
  
Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100
  
FCC-Crystal-Structure-of-Ytterbium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
173.05 amu
  
99+
Atomic Volume
15.00 cm3/mol
  
34
24.79 cm3/mol
  
9
Adjacent Atomic Numbers
  
  
Valence Electron Potential
92.00 (-eV)
  
11
50.30 (-eV)
  
27
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
6.90 g/cm3
  
99+
Density When Liquid (at m.p.)
Not Available
  
6.21 g/cm3
  
99+
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Unknown
  
Ductile, Malleable
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
177.00 nΩ·m
  
21
Electrical Conductivity
0.05 106/cm Ω
  
34
0.04 106/cm Ω
  
38
Electron Affinity
Not Available
  
50.00 kJ/mol
  
21
Specific Heat
0.12 J/(kg K)
  
40
0.15 J/(kg K)
  
36
Molar Heat Capacity
Not Available
  
26.74 J/mol·K
  
25
Thermal Conductivity
47.00 W/m·K
  
32
38.50 W/m·K
  
35
Critical Temperature
Not Available
  
Thermal Expansion
9.90 µm/(m·K)
  
40
26.30 µm/(m·K)
  
14
Enthalpy
  
  
Enthalpy of Vaporization
Not Available
  
128.90 kJ/mol
  
99+
Enthalpy of Fusion
12.34 kJ/mol
  
28
7.66 kJ/mol
  
99+
Enthalpy of Atomization
Not Available
  
180.00 kJ/mol
  
99+
Standard Molar Entropy
198.10 J/mol.K
  
1
59.90 J/mol.K
  
21