Home
Compare Metals


Francium vs Lead


Lead vs Francium


Periodic Table

Symbol
Fr   
Pb   

Group Number
1   
17
14   
4

Period Number
7   
6   

Block
s block   
p block   

Element Family
Alkali   
Post-​Transition   

CAS Number
7440735   
18
7439921   
99+

Space Group Name
Not Available   
Fm_ 3m   

Space Group Number
Not Available   
225.00   
2

Facts

Interesting Facts
  • 223 Francium has the longest half life at 21.8.
  • Francium metal is produced by alpha decay in 227Actinium 227.
  
  • Galena mineral contains almost 87% of Lead metal in it, Galena is sulfide mineral.
  • The best available source of Lead metal today is by recycling automobile batteries.
  

Sources
Formed by Decay Process, Mining   
Earth's crust, Found in Minerals, Mining, Ores of metals, Ores of Minerals   

History
  
  

Who Discovered
Marguerite Perey   
Unknown   

Discovery
In 1939   
In Middle Easterns (7000 BCE)   

Abundance
  
  

Abundance In Universe
Not Available   
1 * 10-6 %   
16

Abundance In Sun
~-9999 %   
~0.000001 %   
18

Abundance In Meteorites
Not Available   
0.00 %   
23

Abundance In Earth's Crust
Not Available   
0.00 %   
26

Abundance In Oceans
Not Available   
0.00 %   
22

Abundance In Humans
Not Available   
0.00 %   
8

Uses

Uses & Benefits
  • Francium has no known uses as it has a half life of only 22 minutes.
  
  • It is also used in insecticides, hair dyes and as an anti-knocking additive for petrol. But all these are banned by the government as Lead metal is known for detrimental to health.
  

Industrial Uses
NA   
Chemical Industry, Electrical Industry, Electronic Industry   

Medical Uses
NA   
Surgical Instruments Manufacturing   

Other Uses
NA   
Alloys   

Biological Properties
  
  

Toxicity
NA   
Toxic   

Present in Human Body
No   
Yes   

In Blood
0.00 Blood/mg dm-3   
37
0.21 Blood/mg dm-3   
11

In Bone
0.00 p.p.m.   
36
30.00 p.p.m.   
10

Physical Properties

Melting Point
27.00 °C   
99+
327.50 °C   
99+

Boiling Point
677.00 °C   
99+
1,740.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
NA   
Gray   

Luster
NA   
Metallic   

Hardness
  
  

Mohs Hardness
Not Available   
1.50   
18

Brinell Hardness
Not Available   
38.00 MPa   
99+

Speed of Sound
Not Available   
1,190.00 m/s   
99+

Optical Properties
  
  

Allotropes
No   
No   

α Allotropes
Not Available   
Not Available   

β Allotropes
Not Available   
Not Available   

γ Allotropes
Not Available   
Not Available   

Chemical Properties

Chemical Formula
Fr   
Pb   

Isotopes
  
  

Known Isotopes
33   
6
35   
4

Electronegativity
  
  

Pauling Electronegativity
0.70   
99+
1.87   
13

Sanderson Electronegativity
Not Available   
2.29   
4

Allred Rochow Electronegativity
0.86   
99+
1.55   
11

Mulliken-Jaffe Electronegativity
0.68   
25
2.41   
2

Allen Electronegativity
0.67   
99+
1.85   
8

Electropositivity
  
  

Pauling Electropositivity
3.30   
1
1.67   
99+

Ionization Energies
  
  

1st Energy Level
380.00 kJ/mol   
99+
715.60 kJ/mol   
31

2nd Energy Level
Not Available   
1,450.50 kJ/mol   
99+

3rd Energy Level
Not Available   
3,081.50 kJ/mol   
23

4th Energy Level
Not Available   
4,083.00 kJ/mol   
35

5th Energy Level
Not Available   
6,640.00 kJ/mol   
20

Electrochemical Equivalent
8.32 g/amp-hr   
1
3.87 g/amp-hr   
9

Electron Work Function
Not Available   
4.25 eV   
21

Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility   
Anti Corrosion, Ionization, Radioactive Isotopes   

Atomic Properties

Atomic Number
87   
31
82   
34

Electron Configuration
[Rn] 7s1   
[Xe] 4f14 5d10 6s2 6p2   

Crystal Structure
Body Centered Cubic (BCC)   
Face Centered Cubic (FCC)   

Crystal Lattice
BCC-Crystal-Structure-.jpg#100   
FCC-Crystal-Structure-of-Lead.jpg#100   

Atom
  
  

Number of Protons
87   
31
82   
34

Number of Neutrons
136   
17
125   
19

Number of Electrons
87   
31
82   
34

Radius of an Atom
  
  

Atomic Radius
Not Available   
175.00 pm   
19

Covalent Radius
260.00 pm   
1
146.00 pm   
38

Van der Waals Radius
348.00 pm   
1
202.00 pm   
27

Atomic Weight
223.00 amu   
27
207.20 amu   
30

Atomic Volume
Not Available   
18.17 cm3/mol   
27

Adjacent Atomic Numbers
  
  

Previous Element
Polonium
  
Thallium
  

Next Element
Radium
  
Bismuth
  

Valence Electron Potential
8.00 (-eV)   
99+
24.20 (-eV)   
99+

Lattice Constant
Not Available   
495.08 pm   
16

Lattice Angles
NA   
π/2, π/2, π/2   

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
1.87 g/cm3   
99+
11.34 g/cm3   
33

Density When Liquid (at m.p.)
Not Available   
10.66 g/cm3   
15

Tensile Strength
Not Available   
12.00 MPa   
20

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
Not Available   
1.64 (Pa)   
7

Elasticity properties
  
  

Shear Modulus
Not Available   
5.60 GPa   
99+

Bulk Modulus
Not Available   
46.00 GPa   
24

Young's Modulus
Not Available   
16.00 GPa   
99+

Poisson Ratio
Not Available   
0.44   
3

Other Mechanical Properties
NA   
Ductile, Malleable   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
Not Available   
11.35   
25

Magnetic Ordering
Paramagnetic   
Diamagnetic   

Electrical Properties
  
  

Electrical Property
Poor Conductor   
Poor Conductor   

Resistivity
3.00 nΩ·m   
99+
208.00 nΩ·m   
16

Electrical Conductivity
0.03 106/cm Ω   
40
0.05 106/cm Ω   
36

Electron Affinity
Not Available   
35.10 kJ/mol   
28

Thermal Properties

Specific Heat
Not Available   
0.13 J/(kg K)   
39

Molar Heat Capacity
Not Available   
26.65 J/mol·K   
26

Thermal Conductivity
15.00 W/m·K   
99+
35.30 W/m·K   
38

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
Not Available   
28.90 µm/(m·K)   
13

Enthalpy
  
  

Enthalpy of Vaporization
Not Available   
179.40 kJ/mol   
99+

Enthalpy of Fusion
Not Available   
4.77 kJ/mol   
99+

Enthalpy of Atomization
71.00 kJ/mol   
99+
194.60 kJ/mol   
99+

Standard Molar Entropy
Not Available   
64.80 J/mol.K   
17

Periodic Table >>
<< All

Compare All Metals

All Metals

All Metals


Compare All Metals