Symbol
Es
Ac
Group Number
133
0
17
👆🏻
Period Number
77
2
7
👆🏻
Block
f block
f block
Element Family
Actinide
Actinide
CAS Number
74299277440348
7429905
54386242
👆🏻
Space Group Name
-
Fm_ 3m
Space Group Number
194.00225.00
11
276
👆🏻
Interesting Facts
- Einsteinium is the transuranic element found in US.
- Only 0.01 mg of Einsteinium was synthesized in 1961.
Actinium glows in the dark due to its radioactivity.
Sources
Made by Bombarding Uranium with Neutrons
Obtained by Treating Radium with Neutrons, Ores of metals
History
Who Discovered
Lawrence Berkeley National Laboratory
Friedrich Oskar Giesel
Discovery
In 1952
In 1902
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
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- Currently known uses of Einsteinium metal are limited to research purpose only.
- Actinium metal has a great source of alpha rays but it is hardly used outside research purpose.
Industrial Uses
-
-
Medical Uses
-
-
Other Uses
Alloys, Nuclear Research, Research Purposes
Alloys, Nuclear Research, Research Purposes
Biological Properties
Toxicity
Toxic
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.0.00 p.p.m.
0
170000
👆🏻
Melting Point
860.00 °C1,227.00 °C
-38.83
3410
👆🏻
Boiling Point
996.00 °C3,200.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silver
Silvery White
Luster
-
-
Hardness
Mohs Hardness
6.006.50
0.2
8.5
👆🏻
Brinell Hardness
240.00 MPa70.00 MPa
0.14
3490
👆🏻
Vickers Hardness
550.00 MPa260.00 MPa
0
3920
👆🏻
Speed of Sound
2,850.00 m/s3,430.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.301.00
0.155
3.41
👆🏻
Reflectivity
63.00 %62.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Es
Ac
Isotopes
Known Isotopes
1629
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.541.10
0
2.6
👆🏻
Sanderson Electronegativity
1.301.10
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.201.00
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.301.10
0.62
2.48
👆🏻
Allen Electronegativity
1.301.10
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.702.90
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
619.00 kJ/mol499.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,216.00 kJ/mol1,170.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,334.00 kJ/mol1,900.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
3,734.00 kJ/mol4,700.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
6,190.00 kJ/mol4,990.00 kJ/mol
392
97510
👆🏻
6th Energy Level
6,190.00 kJ/mol5,750.00 kJ/mol
1007
105800
👆🏻
7th Energy level
6,190.00 kJ/mol5,750.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
6,190.00 kJ/mol5,750.00 kJ/mol
730
125300
👆🏻
9th Energy Level
4,520.00 kJ/mol4,990.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
6,190.00 kJ/mol4,990.00 kJ/mol
392
144300
👆🏻
11th Energy Level
6,190.00 kJ/mol4,990.00 kJ/mol
392
169988
👆🏻
12th Energy Level
61,900.00 kJ/mol49,900.00 kJ/mol
0
189368
👆🏻
13th Energy Level
6,190.00 kJ/mol4,990.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
6,190.00 kJ/mol4,990.00 kJ/mol
380
86450
👆🏻
15th Energy Level
61,900.00 kJ/mol49,900.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
61,900.00 kJ/mol49,900.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
619.00 kJ/mol499.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
6,190.00 kJ/mol4,990.00 kJ/mol
0
134810
👆🏻
19th Energy Level
619.00 kJ/mol499.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
619.00 kJ/mol499.00 kJ/mol
0
171200
👆🏻
21st Energy Level
6,190.00 kJ/mol4,990.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
619.00 kJ/mol499.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
6,190.00 kJ/mol4,990.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
619.40 kJ/mol499.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
619.00 kJ/mol499.00 kJ/mol
0
121900
👆🏻
26th Energy Level
619.40 kJ/mol499.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
619.40 kJ/mol499.00 kJ/mol
0
133800
👆🏻
28th Energy Level
619.40 kJ/mol499.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
619.40 kJ/mol499.00 kJ/mol
0
148100
👆🏻
30th Energy Level
619.40 kJ/mol499.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
4.74 g/amp-hr2.82 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.90 eV4.38 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Atomic Number
9989
3
117
👆🏻
Electron Configuration
[Rn] 5f11 7s2
[Rn] 6d1 7s2
Crystal Structure
Face Centered Cubic (FCC)
Face Centered Cubic (FCC)
Crystal Lattice
Atom
Number of Protons
9989
3
117
👆🏻
Number of Neutrons
153138
4
285
👆🏻
Number of Electrons
9989
3
117
👆🏻
Radius of an Atom
Atomic Radius
186.00 pm195.00 pm
0
348
👆🏻
Covalent Radius
186.00 pm186.00 pm
0
260
👆🏻
Van der Waals Radius
0.00 pm215.00 pm
0
348
👆🏻
Atomic Weight
252.00 amu227.00 amu
6.94
294
👆🏻
Atomic Volume
17.04 cm3/mol22.54 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
0.00 (-eV)38.60 (-eV)
0
392.42
👆🏻
Lattice Constant
582.00 pm567.00 pm
0
891.25
👆🏻
Lattice Angles
-
π/2, π/2, π/2
Lattice C/A Ratio
1.291.89
0.423
1.9
👆🏻
Density
Density At Room Temperature
8.84 g/cm310.00 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
8.84 g/cm310.07 g/cm3
0.512
41
👆🏻
Tensile Strength
0.10 MPa65.00 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
0.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
30.00 GPa25.00 GPa
1.3
222
👆🏻
Bulk Modulus
40.00 GPa94.00 GPa
0
462
👆🏻
Young's Modulus
0.00 GPa130.00 GPa
0
528
👆🏻
Poisson Ratio
0.330.34
0.032
0.47
👆🏻
Other Mechanical Properties
-
-
Magnetic Characteristics
Specific Gravity
8.8410.07
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
-
-
Resistivity
6.30 nΩ·m5.20 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.14 106/cm Ω0.15 106/cm Ω
0
0.63
👆🏻
Electron Affinity
0.00 kJ/mol33.20 kJ/mol
0
222.8
👆🏻
Specific Heat
0.10 J/(kg K)0.12 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
27.20 J/mol·K27.20 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
0.00 W/m·K12.00 W/m·K
0
429
👆🏻
Critical Temperature
1,133.00 K1,323.00 K
26.3
3695
👆🏻
Thermal Expansion
13.50 µm/(m·K)12.10 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
323.80 kJ/mol120.00 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
14.80 kJ/mol14.20 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
-301.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
63.00 J/mol.K56.50 J/mol.K
9.5
198.1
👆🏻