Symbol
Eu
Cs
Group Number
31
0
17
👆🏻
Period Number
66
2
7
👆🏻
Block
f block
s block
Element Family
Lanthanide
Alkali
CAS Number
74405317440462
7429905
54386242
👆🏻
Space Group Name
Im_ 3m
Im_ 3m
Space Group Number
229.00229.00
11
276
👆🏻
Interesting Facts
Europium is used in Euro banknotes for security features.
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
Eugène-Anatole Demarçay
Robert Bunsen and Gustav Kirchhoff
Discovery
In 1896
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
- Europium metals main uses is in the printing of euro banknotes. These notes glow red under UV light.
-
It is used in low energy light bulbs.
- 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
Non 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
822.00 °C28.50 °C
-38.83
3410
👆🏻
Boiling Point
1,597.00 °C678.40 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery Gold
Luster
Lustrous
-
Hardness
Mohs Hardness
2.000.20
0.2
8.5
👆🏻
Brinell Hardness
167.00 MPa0.14 MPa
0.14
3490
👆🏻
Vickers Hardness
167.00 MPa0.14 MPa
0
3920
👆🏻
Speed of Sound
6,320.00 m/s1,630.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.831.93
0.155
3.41
👆🏻
Reflectivity
65.00 %35.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Eu
Cs
Isotopes
Known Isotopes
3136
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.200.79
0
2.6
👆🏻
Sanderson Electronegativity
1.010.22
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.200.86
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.200.62
0.62
2.48
👆🏻
Allen Electronegativity
1.200.66
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.503.21
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
547.10 kJ/mol375.70 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,085.00 kJ/mol2,234.30 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,404.00 kJ/mol3,400.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
4,120.00 kJ/mol375.70 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,471.00 kJ/mol3,750.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,471.00 kJ/mol3,750.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,470.00 kJ/mol3,750.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,470.00 kJ/mol3,760.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,990.00 kJ/mol3,750.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,470.00 kJ/mol3,757.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,470.00 kJ/mol3,757.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,470.00 kJ/mol3,750.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,800.00 kJ/mol3,750.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,470.00 kJ/mol3,750.00 kJ/mol
380
86450
👆🏻
15th Energy Level
54,700.00 kJ/mol37,500.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
54,700.00 kJ/mol375.70 kJ/mol
375.7
109480
👆🏻
17th Energy Level
547.10 kJ/mol375.70 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,470.00 kJ/mol3,757.00 kJ/mol
0
134810
👆🏻
19th Energy Level
547.10 kJ/mol375.70 kJ/mol
375.7
148700
👆🏻
20th Energy Level
547.00 kJ/mol375.00 kJ/mol
0
171200
👆🏻
21st Energy Level
547.10 kJ/mol375.70 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
547.00 kJ/mol375.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
547.10 kJ/mol375.70 kJ/mol
357.6
198800
👆🏻
24th Energy Level
547.10 kJ/mol375.70 kJ/mol
297.3
195200
👆🏻
25th Energy Level
547.00 kJ/mol375.70 kJ/mol
0
121900
👆🏻
26th Energy Level
547.10 kJ/mol375.70 kJ/mol
357.6
127700
👆🏻
27th Energy Level
547.10 kJ/mol375.70 kJ/mol
0
133800
👆🏻
28th Energy Level
580.70 kJ/mol375.70 kJ/mol
297.3
139800
👆🏻
29th Energy Level
547.10 kJ/mol375.70 kJ/mol
0
148100
👆🏻
30th Energy Level
547.10 kJ/mol375.70 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.89 g/amp-hr4.96 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
2.50 eV2.14 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
Chemical Stability, Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Number
6355
3
117
👆🏻
Electron Configuration
[Xe] 4f7 6s2
[Xe] 6s1
Crystal Structure
Body Centered Cubic (BCC)
Body Centered Cubic (BCC)
Crystal Lattice
Atom
Number of Protons
6355
3
117
👆🏻
Number of Neutrons
8978
4
285
👆🏻
Number of Electrons
6355
3
117
👆🏻
Radius of an Atom
Atomic Radius
180.00 pm265.00 pm
0
348
👆🏻
Covalent Radius
198.00 pm244.00 pm
0
260
👆🏻
Van der Waals Radius
233.00 pm343.00 pm
0
348
👆🏻
Atomic Weight
151.96 amu132.91 amu
6.94
294
👆🏻
Atomic Volume
28.90 cm3/mol71.07 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
45.60 (-eV)8.62 (-eV)
0
392.42
👆🏻
Lattice Constant
458.10 pm614.10 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
1.581.87
0.423
1.9
👆🏻
Density
Density At Room Temperature
5.26 g/cm31.93 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
5.13 g/cm31.84 g/cm3
0.512
41
👆🏻
Tensile Strength
120.00 MPa15.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
19.40 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
7.90 GPa30.00 GPa
1.3
222
👆🏻
Bulk Modulus
8.30 GPa1.60 GPa
0
462
👆🏻
Young's Modulus
18.20 GPa1.70 GPa
0
528
👆🏻
Poisson Ratio
0.150.35
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile
Ductile
Magnetic Characteristics
Specific Gravity
5.241.87
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
0.90 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
0.18 J/(kg K)0.24 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
27.66 J/mol·K32.21 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
13.90 W/m·K35.90 W/m·K
0
429
👆🏻
Critical Temperature
1,099.00 K1,938.00 K
26.3
3695
👆🏻
Thermal Expansion
35.00 µm/(m·K)97.00 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
143.50 kJ/mol65.90 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
9.21 kJ/mol2.10 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
180.00 kJ/mol78.20 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
77.80 J/mol.K85.20 J/mol.K
9.5
198.1
👆🏻