Polonium Niobium Comparison
Periodic Table
Symbol
Po
Nb
Group Number
16
2
5
13
Period Number
6
5
Block
p block
d block
Element Family
Post-Transition
Transition Metal
CAS Number
7440086
99+
7440031
99+
Space Group Name
Pm-3m
Im_ 3m
Space Group Number
221.00
3
229.00
1
Facts
Interesting Facts
- 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.
- Niobium metal was used to get called Columbium in past.
- Niobium metal found freely in nature (abundance).
Sources
Mining, Ores of metals
By-product of Tin Extraction, Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Pierre Curie and Marie Curie
Charles Hatchett
Discovery
In 1898
In 1801
Abundance
Abundance In Universe
Not Available
2 * 10-7 %
22
Abundance In Sun
~-9999 %
~0.0000004 %
23
Abundance In Meteorites
Not Available
0.00 %
35
Abundance In Earth's Crust
Not Available
0.00 %
25
Abundance In Oceans
0.00 %
99+
0.00 %
34
Uses
Uses & Benefits
- 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.
- Niobium alloys are used in jet engines and rockets and spacecraft, beams and girders for buildings and oil and gas pipelines.
- It is used superconducting magnets in particles accelerators, NMR and MRI equipment.
Industrial Uses
Aerospace Industry, Ammunition Industry
Aerospace Industry, Ammunition Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
NA
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Highly Toxic
Low Toxic
Present in Human Body
No
Yes
In Blood
0.00 Blood/mg dm-3
37
0.01 Blood/mg dm-3
25
In Bone
0.00 p.p.m.
36
0.07 p.p.m.
25
Physical Properties
Melting Point
254.00 °C
99+
2,468.00 °C
6
Boiling Point
962.00 °C
99+
2,468.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silver
Gray
Luster
NA
Metallic
Hardness
Mohs Hardness
Not Available
6.00
6
Brinell Hardness
Not Available
735.00 MPa
14
Vickers Hardness
Not Available
870.00 MPa
12
Speed of Sound
Not Available
3,480.00 m/s
21
Optical Properties
Allotropes
Yes
No
α Allotropes
α-polonium
Not Available
β Allotropes
β-polonium
Not Available
γ Allotropes
Not Available
Not Available
Chemical Properties
Chemical Formula
Po
Nb
Isotopes
Known Isotopes
29
10
17
22
Electronegativity
Pauling Electronegativity
2.00
7
1.60
23
Sanderson Electronegativity
Not Available
1.42
16
Allred Rochow Electronegativity
1.76
2
1.23
25
Mulliken-Jaffe Electronegativity
2.48
1
Not Available
Allen Electronegativity
2.19
2
1.41
31
Electropositivity
Pauling Electropositivity
2.00
99+
2.40
31
Ionization Energies
1st Energy Level
812.10 kJ/mol
14
652.10 kJ/mol
99+
2nd Energy Level
Not Available
1,380.00 kJ/mol
99+
3rd Energy Level
Not Available
2,416.00 kJ/mol
99+
4th Energy Level
Not Available
3,700.00 kJ/mol
99+
5th Energy Level
Not Available
4,877.00 kJ/mol
36
6th Energy Level
Not Available
9,847.00 kJ/mol
11
7th Energy level
Not Available
12,100.00 kJ/mol
14
Electrochemical Equivalent
3.90 g/amp-hr
8
0.69 g/amp-hr
99+
Electron Work Function
Not Available
4.30 eV
18
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
84
32
41
99+
Electron Configuration
[Xe] 4f14 5d10 6s2 6p4
[Kr] 4d4 5s1
Crystal Structure
Monoclinic (MON)
Body Centered Cubic (BCC)
Crystal Lattice
MON-Crystal-Structure-of-Polonium.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
84
32
41
99+
Number of Neutrons
125
19
52
99+
Number of Electrons
84
32
41
99+
Radius of an Atom
Atomic Radius
168.00 pm
23
146.00 pm
35
Covalent Radius
140.00 pm
99+
164.00 pm
28
Van der Waals Radius
197.00 pm
29
200.00 pm
28
Atomic Weight
209.00 amu
28
92.91 amu
99+
Atomic Volume
22.23 cm3/mol
13
10.87 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
Not Available
104.00 (-eV)
8
Lattice Constant
335.90 pm
99+
330.04 pm
99+
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
9.20 g/cm3
99+
8.57 g/cm3
99+
Density When Liquid (at m.p.)
9.40 g/cm3
19
Not Available
Tensile Strength
Not Available
330.00 MPa
12
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 2000 K
Not Available
0.00 (Pa)
27
Elasticity properties
Shear Modulus
Not Available
38.00 GPa
19
Bulk Modulus
Not Available
170.00 GPa
10
Young's Modulus
Not Available
105.00 GPa
20
Poisson Ratio
Not Available
0.40
4
Other Mechanical Properties
NA
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
9.32
31
8.57
37
Magnetic Ordering
Nonmagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
0.40 nΩ·m
99+
152.00 nΩ·m
23
Electrical Conductivity
0.02 106/cm Ω
99+
0.07 106/cm Ω
28
Electron Affinity
183.30 kJ/mol
3
86.10 kJ/mol
12
Thermal Properties
Specific Heat
0.12 J/(kg K)
40
0.26 J/(kg K)
20
Molar Heat Capacity
26.40 J/mol·K
28
24.60 J/mol·K
99+
Thermal Conductivity
20.00 W/m·K
99+
53.70 W/m·K
29
Critical Temperature
Not Available
Not Available
Thermal Expansion
23.50 µm/(m·K)
16
7.30 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
60.30 kJ/mol
99+
696.60 kJ/mol
4
Enthalpy of Fusion
13.00 kJ/mol
26
27.20 kJ/mol
6
Enthalpy of Atomization
134.00 kJ/mol
99+
745.00 kJ/mol
4
Standard Molar Entropy
Not Available
36.40 J/mol.K
99+
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