Home
Compare Metals


Francium vs Samarium


Samarium vs Francium


Periodic Table

Symbol
Fr  
Sm  

Group Number
1  
17
3  
15

Period Number
7  
6  

Block
s block  
f block  

Element Family
Alkali  
Lanthanide  

CAS Number
7440735  
18
7440199  
99+

Space Group Name
-  
R_ 3m  

Space Group Number
225.00  
3
166.00  
9

Facts

Interesting Facts
  • 223 Francium has the longest half life at 21.8.
  • Francium metal is produced by alpha decay in 227Actinium 227.
  
  • Samarium metals helps stimulating body metabolism.
  • Samarium metals was 1st observed by Jean Charles Galissard de Marignac in Dydimia in 1853.
  

Sources
Formed by Decay Process, Mining  
Found in Minerals, Mining, Ores of Minerals  

History
  
  

Who Discovered
Marguerite Perey  
Lecoq de Boisbaudran  

Discovery
In 1939  
In 1879  

Abundance
  
  

Abundance In Universe
0.00 %  
40
0.00 %  
20

Abundance In Sun
0.00 %  
30
0.00 %  
26

Abundance In Meteorites
0.00 %  
99+
0.00 %  
37

Abundance In Earth's Crust
0.00 %  
99+
0.00 %  
29

Abundance In Oceans
-  
0.00 %  
40

Abundance In Humans
0.00 %  
24
0.00 %  
24

Uses

Uses & Benefits
  • Francium has no known uses as it has a half life of only 22 minutes.
  
  • Magnets of Samarium cobalt alloy are stronger than that of Iron and hence, they are used in microwave application.
  • Samarium metal also used in optical lasers and infrared absorbing glasses and as a neutron absorber.
  

Industrial Uses
-  
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry  

Medical Uses
-  
-  

Other Uses
-  
Alloys, In Nuclear Reactors  

Biological Properties
  
  

Toxicity
-  
Slightly Toxic  

Present in Human Body
No  
Yes  

In Blood
0.00 Blood/mg dm-3  
40
0.01 Blood/mg dm-3  
22

In Bone
0.00 p.p.m.  
99+
0.00 p.p.m.  
99+

Physical

Melting Point
27.00 °C  
99+
1,072.00 °C  
99+

Boiling Point
677.00 °C  
99+
1,900.00 °C  
99+

Appearance
  
  

Physical State
Solid  
Solid  

Color
-  
Silvery White  

Luster
-  
Lustrous  

Hardness
  
  

Mohs Hardness
0.20  
27
5.50  
7

Brinell Hardness
119.00 MPa  
99+
441.00 MPa  
32

Vickers Hardness
300.00 MPa  
99+
412.00 MPa  
40

Speed of Sound
2,440.00 m/s  
99+
2,130.00 m/s  
99+

Optical Properties
  
  

Refractive Index
1.70  
27
1.80  
22

Reflectivity
72.00 %  
11
65.00 %  
18

Allotropes
No  
No  

α Allotropes
-  
-  

β Allotropes
-  
-  

γ Allotropes
-  
-  

Chemical

Chemical Formula
Fr  
Sm  

Isotopes
  
  

Known Isotopes
33  
6
30  
9

Electronegativity
  
  

Pauling Electronegativity
0.70  
99+
1.17  
99+

Sanderson Electronegativity
0.70  
99+
1.17  
33

Allred Rochow Electronegativity
0.86  
99+
1.07  
33

Mulliken-Jaffe Electronegativity
0.68  
99+
1.17  
40

Allen Electronegativity
0.67  
99+
1.17  
99+

Electropositivity
  
  

Pauling Electropositivity
3.30  
1
2.83  
14

Ionization Energies
  
  

1st Energy Level
380.00 kJ/mol  
99+
544.50 kJ/mol  
99+

2nd Energy Level
392.80 kJ/mol  
99+
1,070.00 kJ/mol  
99+

3rd Energy Level
392.80 kJ/mol  
99+
2,260.00 kJ/mol  
99+

4th Energy Level
392.80 kJ/mol  
99+
3,990.00 kJ/mol  
99+

5th Energy Level
392.00 kJ/mol  
99+
5,445.00 kJ/mol  
99+

6th Energy Level
3,920.00 kJ/mol  
99+
5,445.00 kJ/mol  
99+

7th Energy level
3,920.00 kJ/mol  
99+
5,445.00 kJ/mol  
99+

8th Energy Level
3,920.00 kJ/mol  
99+
5,400.00 kJ/mol  
99+

9th Energy Level
3,920.00 kJ/mol  
99+
5,440.00 kJ/mol  
99+

10th Energy Level
392.00 kJ/mol  
99+
5,445.00 kJ/mol  
99+

11th Energy Level
392.00 kJ/mol  
99+
5,445.00 kJ/mol  
99+

12th Energy Level
38,000.00 kJ/mol  
23
5,440.00 kJ/mol  
99+

13th Energy Level
3,920.00 kJ/mol  
99+
5,445.00 kJ/mol  
99+

14th Energy Level
380.00 kJ/mol  
99+
5,450.00 kJ/mol  
99+

15th Energy Level
67,700.00 kJ/mol  
32
54,450.00 kJ/mol  
99+

16th Energy Level
39,200.00 kJ/mol  
99+
54,400.00 kJ/mol  
99+

17th Energy Level
392.00 kJ/mol  
99+
544.50 kJ/mol  
99+

18th Energy Level
3,920.00 kJ/mol  
99+
5,445.00 kJ/mol  
99+

19th Energy Level
392.80 kJ/mol  
99+
544.50 kJ/mol  
99+

20th Energy Level
392.00 kJ/mol  
99+
624.00 kJ/mol  
99+

21st Energy Level
392.00 kJ/mol  
99+
544.50 kJ/mol  
99+

22nd Energy Level
392.00 kJ/mol  
99+
624.00 kJ/mol  
37

23rd Energy Level
392.80 kJ/mol  
99+
544.50 kJ/mol  
99+

24th Energy Level
392.00 kJ/mol  
99+
544.50 kJ/mol  
99+

25th Energy Level
392.00 kJ/mol  
99+
544.00 kJ/mol  
99+

26th Energy Level
392.80 kJ/mol  
99+
544.50 kJ/mol  
99+

27th Energy Level
392.00 kJ/mol  
99+
544.50 kJ/mol  
99+

28th Energy Level
380.00 kJ/mol  
99+
544.50 kJ/mol  
99+

29th Energy Level
392.00 kJ/mol  
99+
544.50 kJ/mol  
99+

30th Energy Level
677.00 kJ/mol  
31
544.00 kJ/mol  
99+

Electrochemical Equivalent
8.32 g/amp-hr  
1
1.87 g/amp-hr  
38

Electron Work Function
4.07 eV  
33
2.70 eV  
99+

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

Atomic

Atomic Number
87  
31
62  
99+

Electron Configuration
[Rn] 7s1  
[Xe] 4f6 6s2  

Crystal Structure
Body Centered Cubic (BCC)  
Rhombohedral (RHO)  

Crystal Lattice
BCC-Crystal-Structure-.jpg#100  
RHO-Crystal-Structure-of-Samarium.jpg#100  

Atom
  
  

Number of Protons
87  
31
62  
99+

Number of Neutrons
136  
18
88  
40

Number of Electrons
87  
31
62  
99+

Radius of an Atom
  
  

Atomic Radius
348.00 pm  
1
180.00 pm  
16

Covalent Radius
260.00 pm  
1
198.00 pm  
13

Van der Waals Radius
348.00 pm  
1
229.00 pm  
25

Atomic Weight
223.00 amu  
27
150.36 amu  
99+

Atomic Volume
71.00 cm3/mol  
2
19.95 cm3/mol  
31

Adjacent Atomic Numbers
  
  

Previous Element
Polonium
  

Next Element
Radium
  
Europium
  

Valence Electron Potential
8.00 (-eV)  
99+
44.80 (-eV)  
38

Lattice Constant
440.00 pm  
21
362.10 pm  
37

Lattice Angles
-  
π/2, π/2, 2 π/3  

Lattice C/A Ratio
1.56  
99+
1.62  
15

Mechanical

Density
  
  

Density At Room Temperature
1.87 g/cm3  
99+
7.52 g/cm3  
99+

Density When Liquid (at m.p.)
1.87 g/cm3  
99+
7.16 g/cm3  
99+

Tensile Strength
50.00 MPa  
38
50.00 MPa  
38

Viscosity
0.00  
25
0.00  
25

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)  
37
0.94 (Pa)  
9

Vapor Pressure at 2000 K
0.00 (Pa)  
24
0.00 (Pa)  
29

Elasticity properties
  
  

Shear Modulus
3.60 GPa  
99+
19.50 GPa  
99+

Bulk Modulus
6.00 GPa  
99+
37.80 GPa  
99+

Young's Modulus
0.00 GPa  
99+
49.70 GPa  
40

Poisson Ratio
0.44  
3
0.27  
19

Other Mechanical Properties
-  
-  

Magnetic

Magnetic Characteristics
  
  

Specific Gravity
0.87  
99+
7.52  
99+

Magnetic Ordering
Paramagnetic  
Paramagnetic  

Permeability
0.00 H/m  
13
0.00 H/m  
9

Susceptibility
0.00  
24
0.00  
24

Electrical Properties
  
  

Electrical Property
Poor Conductor  
Conductor  

Resistivity
3.00 nΩ·m  
99+
0.94 nΩ·m  
99+

Electrical Conductivity
0.03 106/cm Ω  
99+
0.01 106/cm Ω  
99+

Electron Affinity
0.70 kJ/mol  
99+
50.00 kJ/mol  
26

Thermal

Specific Heat
0.15 J/(kg K)  
37
0.20 J/(kg K)  
32

Molar Heat Capacity
27.00 J/mol·K  
29
29.54 J/mol·K  
9

Thermal Conductivity
15.00 W/m·K  
99+
13.30 W/m·K  
99+

Critical Temperature
300.00 K  
99+
1,345.00 K  
99+

Thermal Expansion
18.90 µm/(m·K)  
25
12.70 µm/(m·K)  
39

Enthalpy
  
  

Enthalpy of Vaporization
67.00 kJ/mol  
99+
166.40 kJ/mol  
99+

Enthalpy of Fusion
2.30 kJ/mol  
99+
8.62 kJ/mol  
99+

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

Standard Molar Entropy
42.00 J/mol.K  
99+
69.60 J/mol.K  
15

Periodic Table >>
<< All

Compare Alkali Metals

Alkali Metals

Alkali Metals

» More Alkali Metals

Compare Alkali Metals

» More Compare Alkali Metals