Symbol
Pr
  
Rb
  
Group Number
Not Available
  
Period Number
6
  
5
  
Block
f block
  
s block
  
Element Family
Lanthanide
  
Alkali
  
Space Group Name
P63/mmc
  
Im_ 3m
  
Interesting Facts
- Praseodymium metal is synthetically produced metal.
- Praseodymium is used as possible fuel for radioactive generators.
  
- Rubidium metal is 16th most common element found in the earth crust.
- Rubidium metal also found in minerals as well as seawater.
  
Sources
Found in Minerals, Mining, Ores of Minerals
  
Obtained from Lithium Production.
  
History
  
  
Who Discovered
Not Available
  
Robert Bunsen and Gustav Kirchhoff
  
Discovery
In 1885
  
In 1861
  
Abundance
  
  
Abundance In Sun
~0.0000001 %
  
26
~0.000003 %
  
17
Abundance In Earth's Crust
Abundance In Humans
Not Available
  
Uses & Benefits
- The main use of Praseodymium include alloys. Praseodymium –Magnesium alloy is used in aircraft engines due to its high strength.
-
This metal is also used while making a permanent magnets.
  
- Rubidium's main application is in the glass manufacturing.
- Rubidium can very easily get ionized and hence it is used for ion engines, but it is still less efficient than that of Caesium.
  
Industrial Uses
Chemical Industry
  
NA
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys
  
Alloys, Research Purposes
  
Biological Properties
  
  
Toxicity
Moderately Toxic
  
Non Toxic
  
Present in Human Body
No
  
Yes
  
In Blood
Not Available
  
2.49 Blood/mg dm-3
  
7
In Bone
Not Available
  
5.00 p.p.m.
  
13
Boiling Point
3,130.00 °C
  
27
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Grayish White
  
Grayish White
  
Luster
Metallic
  
NA
  
Hardness
  
  
Mohs Hardness
Not Available
  
Vickers Hardness
Not Available
  
Speed of Sound
2,280.00 m/s
  
40
1,300.00 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
Pr
  
Rb
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
527.00 kJ/mol
  
99+
403.00 kJ/mol
  
99+
2nd Energy Level
1,020.00 kJ/mol
  
99+
2,633.00 kJ/mol
  
6
3rd Energy Level
2,086.00 kJ/mol
  
99+
3,860.00 kJ/mol
  
11
4th Energy Level
3,761.00 kJ/mol
  
99+
5,080.00 kJ/mol
  
18
5th Energy Level
5,551.00 kJ/mol
  
29
6,850.00 kJ/mol
  
19
6th Energy Level
Not Available
  
8,140.00 kJ/mol
  
20
7th Energy level
Not Available
  
9,570.00 kJ/mol
  
20
8th Energy Level
Not Available
  
13,120.00 kJ/mol
  
17
9th Energy Level
Not Available
  
14,500.00 kJ/mol
  
18
10th Energy Level
Not Available
  
26,740.00 kJ/mol
  
6
Electrochemical Equivalent
1.75 g/amp-hr
  
40
3.19 g/amp-hr
  
14
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes
  
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Xe] 4f3 6s2
  
[Kr] 5s1
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
HCP-Crystal-Structure-of-Praseodymium.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
140.91 amu
  
99+
Atomic Volume
20.80 cm3/mol
  
15
55.90 cm3/mol
  
2
Adjacent Atomic Numbers
  
  
Valence Electron Potential
42.64 (-eV)
  
99+
9.47 (-eV)
  
99+
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
6.77 g/cm3
  
99+
1.53 g/cm3
  
99+
Density When Liquid (at m.p.)
1.46 g/cm3
  
99+
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile, Malleable
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
128.00 nΩ·m
  
26
Electrical Conductivity
0.01 106/cm Ω
  
99+
0.08 106/cm Ω
  
24
Electron Affinity
50.00 kJ/mol
  
21
46.90 kJ/mol
  
24
Specific Heat
0.19 J/(kg K)
  
32
0.36 J/(kg K)
  
17
Molar Heat Capacity
27.20 J/mol·K
  
18
31.06 J/mol·K
  
5
Thermal Conductivity
12.50 W/m·K
  
99+
58.20 W/m·K
  
26
Critical Temperature
Not Available
  
Thermal Expansion
6.70 µm/(m·K)
  
99+
90.00 µm/(m·K)
  
2
Enthalpy
  
  
Enthalpy of Vaporization
296.80 kJ/mol
  
29
69.20 kJ/mol
  
99+
Enthalpy of Fusion
6.89 kJ/mol
  
99+
2.19 kJ/mol
  
99+
Enthalpy of Atomization
368.00 kJ/mol
  
24
82.00 kJ/mol
  
99+
Standard Molar Entropy
73.20 J/mol.K
  
10
76.80 J/mol.K
  
5