Symbol
Ce
Po
Group Number
316
0
17
👆🏻
Period Number
66
2
7
👆🏻
Block
f block
p block
Element Family
Lanthanide
Post-Transition
CAS Number
74404517440086
7429905
54386242
👆🏻
Space Group Name
P63/mmc
Pm-3m
Space Group Number
194.00221.00
11
276
👆🏻
Interesting Facts
- Cerium is a rare earth metal but still it is not rare at all.
- It’s non-toxic compound Cerium sulfide has a rich red color and it is used as a pigment.
- Cerium metal is also used in Flat screen TVs, light bulb, floodlights, etc.
- Polonium was the first radioactive element to be discovered.
- Polonium element and its compounds are highly radioactive.
- Its alloy with Beryllium provides source of neutrons.
Sources
Found in Minerals, Mining, Ores of Minerals
Mining, Ores of metals
History
Who Discovered
Martin Heinrich Klaproth, Jöns Jakob Berzelius, Wilhelm Hisinger
Pierre Curie and Marie Curie
Discovery
In 1803
In 1898
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %-
0
0.1
👆🏻
Abundance In Meteorites
0.00 %-
0
22
👆🏻
Abundance In Earth's Crust
0.01 %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
- It is used to include flints for cigarette lighters.
- Its compound Cerium (Ill) Oxide is used as a catalyst; it is put inside the walls of the oven as it prevents from the buildup of cooking residues.
- Polonium metal has different Allotropes, it is used in antistatic devices and for research purpose.
- A 1 gram of Polonium can reach a temperature of 500°C, hence it is used as a heat source for space equipment.
Industrial Uses
Chemical Industry
Aerospace Industry, Ammunition Industry
Medical Uses
Medical Research
-
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Moderately Toxic
Highly Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.00 Blood/mg dm-3
0
1970
👆🏻
In Bone
2.70 p.p.m.0.00 p.p.m.
0
170000
👆🏻
Melting Point
795.00 °C254.00 °C
-38.83
3410
👆🏻
Boiling Point
3,257.00 °C962.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silver
Luster
Lustrous
-
Hardness
Mohs Hardness
2.502.50
0.2
8.5
👆🏻
Brinell Hardness
186.00 MPa70.00 MPa
0.14
3490
👆🏻
Vickers Hardness
210.00 MPa30.00 MPa
0
3920
👆🏻
Speed of Sound
2,100.00 m/s2,260.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
2.202.70
0.155
3.41
👆🏻
Reflectivity
68.00 %50.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
α-polonium
β Allotropes
-
β-polonium
γ Allotropes
-
-
Chemical Formula
Ce
Po
Isotopes
Known Isotopes
3029
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.122.00
0
2.6
👆🏻
Sanderson Electronegativity
1.122.00
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.081.76
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.122.48
0.62
2.48
👆🏻
Allen Electronegativity
1.122.19
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.882.00
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
534.40 kJ/mol812.10 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,050.00 kJ/mol1,833.20 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
1,949.00 kJ/mol812.10 kJ/mol
392.8
34230
👆🏻
4th Energy Level
3,547.00 kJ/mol8,121.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
6,325.00 kJ/mol8,120.00 kJ/mol
392
97510
👆🏻
6th Energy Level
7,490.00 kJ/mol8,120.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,340.00 kJ/mol8,120.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,340.00 kJ/mol8,120.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,340.00 kJ/mol8,120.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,340.00 kJ/mol8,120.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,340.00 kJ/mol8,120.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,340.00 kJ/mol8,120.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,650.00 kJ/mol8,120.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,340.00 kJ/mol8,120.00 kJ/mol
380
86450
👆🏻
15th Energy Level
53,400.00 kJ/mol81,200.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
53,400.00 kJ/mol81,200.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
534.40 kJ/mol812.10 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,340.00 kJ/mol8,120.00 kJ/mol
0
134810
👆🏻
19th Energy Level
534.40 kJ/mol812.10 kJ/mol
375.7
148700
👆🏻
20th Energy Level
534.00 kJ/mol812.00 kJ/mol
0
171200
👆🏻
21st Energy Level
5,346.00 kJ/mol812.10 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
594.00 kJ/mol812.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
5,346.00 kJ/mol812.10 kJ/mol
357.6
198800
👆🏻
24th Energy Level
565.50 kJ/mol812.10 kJ/mol
297.3
195200
👆🏻
25th Energy Level
534.40 kJ/mol812.10 kJ/mol
0
121900
👆🏻
26th Energy Level
565.50 kJ/mol812.10 kJ/mol
357.6
127700
👆🏻
27th Energy Level
565.50 kJ/mol812.10 kJ/mol
0
133800
👆🏻
28th Energy Level
565.50 kJ/mol812.10 kJ/mol
297.3
139800
👆🏻
29th Energy Level
565.50 kJ/mol812.10 kJ/mol
0
148100
👆🏻
30th Energy Level
594.00 kJ/mol812.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.74 g/amp-hr3.90 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
2.84 eV4.50 eV
2.14
6
👆🏻
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Ionization, Radioactive Isotopes, Solubility
Atomic Number
5884
3
117
👆🏻
Electron Configuration
[Xe] 4f1 5d1 6s2
[Xe] 4f14 5d10 6s2 6p4
Crystal Structure
Double Hexagonal Close Packed (DHCP)
Monoclinic (MON)
Crystal Lattice
Atom
Number of Protons
5884
3
117
👆🏻
Number of Neutrons
82125
4
285
👆🏻
Number of Electrons
5884
3
117
👆🏻
Radius of an Atom
Atomic Radius
181.80 pm168.00 pm
0
348
👆🏻
Covalent Radius
204.00 pm140.00 pm
0
260
👆🏻
Van der Waals Radius
235.00 pm197.00 pm
0
348
👆🏻
Atomic Weight
140.12 amu209.00 amu
6.94
294
👆🏻
Atomic Volume
20.67 cm3/mol22.23 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
41.78 (-eV)9.30 (-eV)
0
392.42
👆🏻
Lattice Constant
362.00 pm335.90 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, π/2
Lattice C/A Ratio
1.591.46
0.423
1.9
👆🏻
Density
Density At Room Temperature
6.77 g/cm39.20 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
6.55 g/cm39.40 g/cm3
0.512
41
👆🏻
Tensile Strength
270.00 MPa50.00 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
1.04 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
13.50 GPa24.00 GPa
1.3
222
👆🏻
Bulk Modulus
21.50 GPa46.00 GPa
0
462
👆🏻
Young's Modulus
33.60 GPa46.00 GPa
0
528
👆🏻
Poisson Ratio
0.240.23
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile, Malleable
-
Magnetic Characteristics
Specific Gravity
6.779.32
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Nonmagnetic
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
Conductor
Resistivity
828.00 nΩ·m0.40 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.01 106/cm Ω0.02 106/cm Ω
0
0.63
👆🏻
Electron Affinity
50.00 kJ/mol183.30 kJ/mol
0
222.8
👆🏻
Specific Heat
0.19 J/(kg K)0.12 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
26.94 J/mol·K26.40 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
11.30 W/m·K20.00 W/m·K
0
429
👆🏻
Critical Temperature
1,071.00 K527.00 K
26.3
3695
👆🏻
Thermal Expansion
6.30 µm/(m·K)23.50 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
414.00 kJ/mol60.30 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
5.46 kJ/mol13.00 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
381.00 kJ/mol134.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
72.00 J/mol.K41.10 J/mol.K
9.5
198.1
👆🏻