Symbol
Th
Ac
Group Number
03
0
17
👆🏻
Period Number
77
2
7
👆🏻
Block
f block
f block
Element Family
Actinide
Actinide
CAS Number
74403267440348
7429905
54386242
👆🏻
Space Group Name
P63/mmc
Fm_ 3m
Space Group Number
194.00225.00
11
276
👆🏻
Interesting Facts
- Thorium metal is used as an alternate option over Uranium for nuclear fuel.
- Thorium metals appearance (silvery white, soft) is somewhat similar to Lead metal.
Actinium glows in the dark due to its radioactivity.
Sources
Found in Minerals, Mining
Obtained by Treating Radium with Neutrons, Ores of metals
History
Who Discovered
Jöns Jakob Berzelius
Friedrich Oskar Giesel
Discovery
In 1829
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
0.05 %0.00 %
0
22
👆🏻
Abundance In Earth's Crust
0.66 %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
- Thorium metal is used as an allying agent for Magnesium, It imparts greater strength and resistance to temperature.
-
compound of this metal Thorium oxide is used as an industrial catalyst.
- Actinium metal has a great source of alpha rays but it is hardly used outside research purpose.
Industrial Uses
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry
-
Medical Uses
Dentistry, Surgical Instruments Manufacturing
-
Other Uses
Alloys, Jewellery, Sculptures, Statues
Alloys, Nuclear Research, Research Purposes
Biological Properties
Toxicity
Non Toxic
Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.00 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.02 p.p.m.0.00 p.p.m.
0
170000
👆🏻
Melting Point
1,750.00 °C1,227.00 °C
-38.83
3410
👆🏻
Boiling Point
4,790.00 °C3,200.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silver
Silvery White
Luster
-
-
Hardness
Mohs Hardness
3.006.50
0.2
8.5
👆🏻
Brinell Hardness
390.00 MPa70.00 MPa
0.14
3490
👆🏻
Vickers Hardness
295.00 MPa260.00 MPa
0
3920
👆🏻
Speed of Sound
2,490.00 m/s3,430.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.601.00
0.155
3.41
👆🏻
Reflectivity
15.00 %62.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Th
Ac
Isotopes
Known Isotopes
2829
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.301.10
0
2.6
👆🏻
Sanderson Electronegativity
1.301.10
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.111.00
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
587.00 kJ/mol499.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,110.00 kJ/mol1,170.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
1,978.00 kJ/mol1,900.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
2,780.00 kJ/mol4,700.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,870.00 kJ/mol4,990.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,870.00 kJ/mol5,750.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,870.00 kJ/mol5,750.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,870.00 kJ/mol5,750.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,870.00 kJ/mol4,990.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,870.00 kJ/mol4,990.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,870.00 kJ/mol4,990.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,870.00 kJ/mol49,900.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,870.00 kJ/mol4,990.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,870.00 kJ/mol4,990.00 kJ/mol
380
86450
👆🏻
15th Energy Level
58,700.00 kJ/mol49,900.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
58,700.00 kJ/mol49,900.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
587.40 kJ/mol499.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,870.00 kJ/mol4,990.00 kJ/mol
0
134810
👆🏻
19th Energy Level
587.00 kJ/mol499.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
587.00 kJ/mol499.00 kJ/mol
0
171200
👆🏻
21st Energy Level
587.00 kJ/mol4,990.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
587.00 kJ/mol499.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
587.00 kJ/mol4,990.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
587.00 kJ/mol499.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
587.00 kJ/mol499.00 kJ/mol
0
121900
👆🏻
26th Energy Level
587.40 kJ/mol499.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
587.40 kJ/mol499.00 kJ/mol
0
133800
👆🏻
28th Energy Level
587.40 kJ/mol499.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
587.00 kJ/mol499.00 kJ/mol
0
148100
👆🏻
30th Energy Level
587.40 kJ/mol499.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
2.16 g/amp-hr2.82 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
3.41 eV4.38 eV
2.14
6
👆🏻
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Atomic Number
9089
3
117
👆🏻
Electron Configuration
[Rn] 6d2 7s2
[Rn] 6d1 7s2
Crystal Structure
Face Centered Cubic (FCC)
Face Centered Cubic (FCC)
Crystal Lattice
Atom
Number of Protons
9089
3
117
👆🏻
Number of Neutrons
142138
4
285
👆🏻
Number of Electrons
9089
3
117
👆🏻
Radius of an Atom
Atomic Radius
179.80 pm195.00 pm
0
348
👆🏻
Covalent Radius
206.00 pm186.00 pm
0
260
👆🏻
Van der Waals Radius
237.00 pm215.00 pm
0
348
👆🏻
Atomic Weight
232.04 amu227.00 amu
6.94
294
👆🏻
Atomic Volume
19.90 cm3/mol22.54 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
59.30 (-eV)38.60 (-eV)
0
392.42
👆🏻
Lattice Constant
508.42 pm567.00 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
1.101.89
0.423
1.9
👆🏻
Density
Density At Room Temperature
11.72 g/cm310.00 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
11.72 g/cm310.07 g/cm3
0.512
41
👆🏻
Tensile Strength
75.00 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
31.00 GPa25.00 GPa
1.3
222
👆🏻
Bulk Modulus
54.00 GPa94.00 GPa
0
462
👆🏻
Young's Modulus
79.00 GPa130.00 GPa
0
528
👆🏻
Poisson Ratio
0.270.34
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile
-
Magnetic Characteristics
Specific Gravity
11.7010.07
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
Superconductor
-
Resistivity
157.00 nΩ·m5.20 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.07 106/cm Ω0.15 106/cm Ω
0
0.63
👆🏻
Electron Affinity
0.00 kJ/mol33.20 kJ/mol
0
222.8
👆🏻
Specific Heat
0.12 J/(kg K)0.12 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
26.23 J/mol·K27.20 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
54.00 W/m·K12.00 W/m·K
0
429
👆🏻
Critical Temperature
2,023.00 K1,323.00 K
26.3
3695
👆🏻
Thermal Expansion
11.00 µm/(m·K)12.10 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
429.00 kJ/mol120.00 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
15.48 kJ/mol14.20 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
468.60 kJ/mol301.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
27.30 J/mol.K56.50 J/mol.K
9.5
198.1
👆🏻