Francium vs Lanthanum
Periodic Table
Symbol
Fr
La
Group Number
1
17
Not Available
Period Number
7
6
Block
s block
f block
Element Family
Alkali
Lanthanide
CAS Number
7440735
18
7439910
99+
Space Group Name
Not Available
P63/mmc
Space Group Number
Not Available
194.00
5
Facts
Interesting Facts
- 223 Francium has the longest half life at 21.8.
- Francium metal is produced by alpha decay in 227Actinium 227.
- Lanthanum metal is highly malleable, ductile and sectile.
- If exposed to air Lanthanum metal oxidizes rapidly.
Sources
Formed by Decay Process, Mining
Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Marguerite Perey
Carl Gustaf Mosander
Discovery
In 1939
In 1838
Abundance
Abundance In Universe
Not Available
2 * 10-7 %
22
Abundance In Sun
~-9999 %
~0.0000002 %
25
Abundance In Meteorites
Not Available
0.00 %
32
Abundance In Earth's Crust
Not Available
0.00 %
19
Abundance In Oceans
Not Available
0.00 %
29
Uses
Uses & Benefits
- Francium has no known uses as it has a half life of only 22 minutes.
- It has no commercial uses, but its alloys are in high demand. Lanthanum and Nickel alloy is used for the hydrogen gas storage.
- The best-known use for mischmetal alloy of Lanthanum is; as a ‘flints’ for cigarette lighters.
Industrial Uses
NA
Electrical Industry, Electronic Industry
Medical Uses
NA
NA
Other Uses
NA
Alloys, Mirror Manufacturing
Biological Properties
Toxicity
NA
Low Toxic
Present in Human Body
No
Yes
In Blood
0.00 Blood/mg dm-3
37
Not Available
In Bone
0.00 p.p.m.
36
0.08 p.p.m.
24
Physical Properties
Melting Point
27.00 °C
99+
920.00 °C
99+
Boiling Point
677.00 °C
99+
3,469.00 °C
18
Appearance
Physical State
Solid
Solid
Color
NA
Silvery White
Luster
NA
NA
Hardness
Mohs Hardness
Not Available
2.50
14
Brinell Hardness
Not Available
350.00 MPa
30
Vickers Hardness
Not Available
360.00 MPa
26
Speed of Sound
Not Available
2,475.00 m/s
37
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
La
Isotopes
Known Isotopes
33
6
31
8
Electronegativity
Pauling Electronegativity
0.70
99+
1.10
99+
Allred Rochow Electronegativity
0.86
99+
1.08
31
Mulliken-Jaffe Electronegativity
0.68
25
Not Available
Allen Electronegativity
0.67
99+
Not Available
Electropositivity
Pauling Electropositivity
3.30
1
2.90
10
Ionization Energies
1st Energy Level
380.00 kJ/mol
99+
538.10 kJ/mol
99+
2nd Energy Level
Not Available
1,067.00 kJ/mol
99+
3rd Energy Level
Not Available
1,850.30 kJ/mol
99+
4th Energy Level
Not Available
4,819.00 kJ/mol
22
5th Energy Level
Not Available
5,940.00 kJ/mol
25
Electrochemical Equivalent
8.32 g/amp-hr
1
1.73 g/amp-hr
99+
Electron Work Function
Not Available
3.50 eV
31
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
87
31
57
99+
Electron Configuration
[Rn] 7s1
[Xe] 5d2 6s2
Crystal Structure
Body Centered Cubic (BCC)
Double Hexagonal Close Packed (DHCP)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
DHCP-Crystal-Structure-of-Lanthanum.jpg#100
Atom
Number of Protons
87
31
57
99+
Number of Neutrons
136
17
82
99+
Number of Electrons
87
31
57
99+
Radius of an Atom
Atomic Radius
Not Available
187.00 pm
8
Covalent Radius
260.00 pm
1
207.00 pm
6
Van der Waals Radius
348.00 pm
1
240.00 pm
13
Atomic Weight
223.00 amu
27
138.91 amu
99+
Atomic Volume
Not Available
20.73 cm3/mol
16
Adjacent Atomic Numbers
Valence Electron Potential
8.00 (-eV)
99+
40.71 (-eV)
99+
Lattice Constant
Not Available
377.20 pm
28
Lattice Angles
NA
π/2, π/2, 2 π/3
Lattice C/A Ratio
Not Available
1.62
2
Mechanical Properties
Density
Density At Room Temperature
1.87 g/cm3
99+
6.16 g/cm3
99+
Density When Liquid (at m.p.)
Not Available
5.94 g/cm3
99+
Tensile Strength
Not Available
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 2000 K
Not Available
0.98 (Pa)
15
Elasticity properties
Shear Modulus
Not Available
14.30 GPa
40
Bulk Modulus
Not Available
27.90 GPa
99+
Young's Modulus
Not Available
36.60 GPa
99+
Poisson Ratio
Not Available
0.28
17
Other Mechanical Properties
NA
Ductile
Magnetic Properties
Magnetic Characteristics
Specific Gravity
Not Available
6.17
99+
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Poor Conductor
Conductor
Resistivity
3.00 nΩ·m
99+
615.00 nΩ·m
7
Electrical Conductivity
0.03 106/cm Ω
40
0.01 106/cm Ω
99+
Electron Affinity
Not Available
48.00 kJ/mol
23
Thermal Properties
Specific Heat
Not Available
0.19 J/(kg K)
32
Molar Heat Capacity
Not Available
27.11 J/mol·K
21
Thermal Conductivity
15.00 W/m·K
99+
13.40 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
Not Available
12.10 µm/(m·K)
32
Enthalpy
Enthalpy of Vaporization
Not Available
399.60 kJ/mol
17
Enthalpy of Fusion
Not Available
6.20 kJ/mol
99+
Enthalpy of Atomization
71.00 kJ/mol
99+
431.00 kJ/mol
16
Standard Molar Entropy
Not Available
56.90 J/mol.K
23
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