Symbol
Pr
Cs
Group Number
31
0
17
👆🏻
Period Number
66
2
7
👆🏻
Block
f block
s block
Element Family
Lanthanide
Alkali
CAS Number
74401007440462
7429905
54386242
👆🏻
Space Group Name
P63/mmc
Im_ 3m
Space Group Number
194.00229.00
11
276
👆🏻
Interesting Facts
- Praseodymium metal is synthetically produced metal.
- Praseodymium is used as possible fuel for radioactive generators.
Cesium is the most alkaline metal and is used in atomic clocks.
Sources
Found in Minerals, Mining, Ores of Minerals
Earth's crust, Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
-
Robert Bunsen and Gustav Kirchhoff
Discovery
In 1885
In 1860
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %0.00 %
0
0.1
👆🏻
Abundance In Meteorites
0.00 %0.00 %
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
0.00 %0.00 %
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
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.
- The most common use of cesium metal is as a drilling fluid. It is also used in optical glass manufacturing.
-
In vacuum tubes and radiation monitor equipment this metal is used as a catalyst promoter.
Industrial Uses
Chemical Industry
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
Medical Uses
-
-
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Moderately Toxic
Mildly Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.00 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.00 p.p.m.0.05 p.p.m.
0
170000
👆🏻
Melting Point
935.00 °C28.50 °C
-38.83
3410
👆🏻
Boiling Point
3,130.00 °C678.40 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Grayish White
Silvery Gold
Luster
Metallic
-
Hardness
Mohs Hardness
4.000.20
0.2
8.5
👆🏻
Brinell Hardness
481.00 MPa0.14 MPa
0.14
3490
👆🏻
Vickers Hardness
400.00 MPa0.14 MPa
0
3920
👆🏻
Speed of Sound
2,280.00 m/s1,630.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.641.93
0.155
3.41
👆🏻
Reflectivity
60.00 %35.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Pr
Cs
Isotopes
Known Isotopes
3136
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.130.79
0
2.6
👆🏻
Sanderson Electronegativity
1.130.22
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.070.86
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.130.62
0.62
2.48
👆🏻
Allen Electronegativity
1.130.66
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.873.21
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
527.00 kJ/mol375.70 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,020.00 kJ/mol2,234.30 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,086.00 kJ/mol3,400.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
3,761.00 kJ/mol375.70 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,551.00 kJ/mol3,750.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,270.00 kJ/mol3,750.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,270.00 kJ/mol3,750.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,270.00 kJ/mol3,760.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,270.00 kJ/mol3,750.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,270.00 kJ/mol3,757.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,274.00 kJ/mol3,757.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,270.00 kJ/mol3,750.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,270.00 kJ/mol3,750.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,270.00 kJ/mol3,750.00 kJ/mol
380
86450
👆🏻
15th Energy Level
52,700.00 kJ/mol37,500.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
52,700.00 kJ/mol375.70 kJ/mol
375.7
109480
👆🏻
17th Energy Level
527.30 kJ/mol375.70 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,270.00 kJ/mol3,757.00 kJ/mol
0
134810
👆🏻
19th Energy Level
527.30 kJ/mol375.70 kJ/mol
375.7
148700
👆🏻
20th Energy Level
527.00 kJ/mol375.00 kJ/mol
0
171200
👆🏻
21st Energy Level
527.00 kJ/mol375.70 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
527.00 kJ/mol375.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
527.00 kJ/mol375.70 kJ/mol
357.6
198800
👆🏻
24th Energy Level
527.40 kJ/mol375.70 kJ/mol
297.3
195200
👆🏻
25th Energy Level
527.00 kJ/mol375.70 kJ/mol
0
121900
👆🏻
26th Energy Level
527.40 kJ/mol375.70 kJ/mol
357.6
127700
👆🏻
27th Energy Level
527.40 kJ/mol375.70 kJ/mol
0
133800
👆🏻
28th Energy Level
527.40 kJ/mol375.70 kJ/mol
297.3
139800
👆🏻
29th Energy Level
527.00 kJ/mol375.70 kJ/mol
0
148100
👆🏻
30th Energy Level
527.00 kJ/mol375.70 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.75 g/amp-hr4.96 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
2.70 eV2.14 eV
2.14
6
👆🏻
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes
Chemical Stability, Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Number
5955
3
117
👆🏻
Electron Configuration
[Xe] 4f3 6s2
[Xe] 6s1
Crystal Structure
Hexagonal Close Packed (HCP)
Body Centered Cubic (BCC)
Crystal Lattice
Atom
Number of Protons
5955
3
117
👆🏻
Number of Neutrons
8278
4
285
👆🏻
Number of Electrons
5955
3
117
👆🏻
Radius of an Atom
Atomic Radius
182.00 pm265.00 pm
0
348
👆🏻
Covalent Radius
203.00 pm244.00 pm
0
260
👆🏻
Van der Waals Radius
239.00 pm343.00 pm
0
348
👆🏻
Atomic Weight
140.91 amu132.91 amu
6.94
294
👆🏻
Atomic Volume
20.80 cm3/mol71.07 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
42.64 (-eV)8.62 (-eV)
0
392.42
👆🏻
Lattice Constant
367.25 pm614.10 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, π/2
Lattice C/A Ratio
1.611.87
0.423
1.9
👆🏻
Density
Density At Room Temperature
6.77 g/cm31.93 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
6.50 g/cm31.84 g/cm3
0.512
41
👆🏻
Tensile Strength
55.00 MPa15.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
13.20 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
14.80 GPa30.00 GPa
1.3
222
👆🏻
Bulk Modulus
28.80 GPa1.60 GPa
0
462
👆🏻
Young's Modulus
37.30 GPa1.70 GPa
0
528
👆🏻
Poisson Ratio
0.280.35
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile, Malleable
Ductile
Magnetic Characteristics
Specific Gravity
6.771.87
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Paramagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
Conductor
Semiconductor
Resistivity
0.70 nΩ·m205.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.01 106/cm Ω0.05 106/cm Ω
0
0.63
👆🏻
Electron Affinity
50.00 kJ/mol45.50 kJ/mol
0
222.8
👆🏻
Specific Heat
0.19 J/(kg K)0.24 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
27.20 J/mol·K32.21 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
12.50 W/m·K35.90 W/m·K
0
429
👆🏻
Critical Temperature
1,208.00 K1,938.00 K
26.3
3695
👆🏻
Thermal Expansion
6.70 µm/(m·K)97.00 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
296.80 kJ/mol65.90 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
6.89 kJ/mol2.10 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
368.00 kJ/mol78.20 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
73.20 J/mol.K85.20 J/mol.K
9.5
198.1
👆🏻