Symbol
Fr
Be
Group Number
12
0
17
👆🏻
Period Number
72
2
7
👆🏻
Block
s block
s block
Element Family
Alkali
Alkaline Earth
CAS Number
74407357440417
7429905
54386242
👆🏻
Space Group Name
-
P63/mmc
Space Group Number
225.00194.00
11
276
👆🏻
Interesting Facts
- 223 Francium has the longest half life at 21.8.
- Francium metal is produced by alpha decay in 227Actinium 227.
- Beryllium is best anti corrosion metal.
- Beryllium is the lightest metal and still it is stronger than steel.
- It also finds various applications in Nuclear reactors as a reflector.
Sources
Formed by Decay Process, Mining
Earth's crust, Found in Minerals, Mining, Ores of metals, Ores of Minerals
History
Who Discovered
Marguerite Perey
Louis Nicolas Vauquelin
Discovery
In 1939
In 1797
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %0.00 %
0
0.1
👆🏻
Abundance In Meteorites
0.00 %0.00 %
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
-0.00 %
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- Francium has no known uses as it has a half life of only 22 minutes.
- Its alloys with copper or nickel are used in manufacturing Gyroscopes, springs, electrical contact and non sparking tools.
- Beryllium Alloys are used as a material for aircraft, missiles, spacecraft and satellite.
Industrial Uses
-
Aerospace Industry, Ammunition Industry, Automobile Industry, Electrical Industry, Electronic Industry
Medical Uses
-
-
Other Uses
-
Alloys
Biological Properties
Toxicity
-
Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.00 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.00 p.p.m.0.00 p.p.m.
0
170000
👆🏻
Melting Point
27.00 °C1,278.00 °C
-38.83
3410
👆🏻
Boiling Point
677.00 °C2,970.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
-
White Gray
Luster
-
Metallic
Hardness
Mohs Hardness
0.205.50
0.2
8.5
👆🏻
Brinell Hardness
119.00 MPa590.00 MPa
0.14
3490
👆🏻
Vickers Hardness
300.00 MPa1,670.00 MPa
0
3920
👆🏻
Speed of Sound
2,440.00 m/s12,890.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.701.56
0.155
3.41
👆🏻
Reflectivity
72.00 %65.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Fr
Be
Isotopes
Known Isotopes
339
0
38
👆🏻
Electronegativity
Pauling Electronegativity
0.701.57
0
2.6
👆🏻
Sanderson Electronegativity
0.701.81
0.22
2.56
👆🏻
Allred Rochow Electronegativity
0.861.47
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
0.681.54
0.62
2.48
👆🏻
Allen Electronegativity
0.671.58
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
3.302.43
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
380.00 kJ/mol899.50 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
392.80 kJ/mol1,757.10 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
392.80 kJ/mol14,848.70 kJ/mol
392.8
34230
👆🏻
4th Energy Level
392.80 kJ/mol21,006.60 kJ/mol
375.7
37066
👆🏻
5th Energy Level
392.00 kJ/mol2,970.00 kJ/mol
392
97510
👆🏻
6th Energy Level
3,920.00 kJ/mol1,470.00 kJ/mol
1007
105800
👆🏻
7th Energy level
3,920.00 kJ/mol2,970.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
3,920.00 kJ/mol2,970.00 kJ/mol
730
125300
👆🏻
9th Energy Level
3,920.00 kJ/mol2,970.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
392.00 kJ/mol2,970.00 kJ/mol
392
144300
👆🏻
11th Energy Level
392.00 kJ/mol2,970.00 kJ/mol
392
169988
👆🏻
12th Energy Level
38,000.00 kJ/mol29,700.00 kJ/mol
0
189368
👆🏻
13th Energy Level
3,920.00 kJ/mol2,970.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
380.00 kJ/mol2,970.00 kJ/mol
380
86450
👆🏻
15th Energy Level
67,700.00 kJ/mol89,900.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
39,200.00 kJ/mol89,900.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
392.00 kJ/mol2,970.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
3,920.00 kJ/mol8,995.00 kJ/mol
0
134810
👆🏻
19th Energy Level
392.80 kJ/mol899.50 kJ/mol
375.7
148700
👆🏻
20th Energy Level
392.00 kJ/mol899.00 kJ/mol
0
171200
👆🏻
21st Energy Level
392.00 kJ/mol2,970.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
392.00 kJ/mol899.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
392.80 kJ/mol2,970.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
392.00 kJ/mol297.30 kJ/mol
297.3
195200
👆🏻
25th Energy Level
392.00 kJ/mol2,970.00 kJ/mol
0
121900
👆🏻
26th Energy Level
392.80 kJ/mol2,970.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
392.00 kJ/mol297.30 kJ/mol
0
133800
👆🏻
28th Energy Level
380.00 kJ/mol297.30 kJ/mol
297.3
139800
👆🏻
29th Energy Level
392.00 kJ/mol2,970.00 kJ/mol
0
148100
👆🏻
30th Energy Level
677.00 kJ/mol2,970.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
8.32 g/amp-hr0.17 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.07 eV4.98 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Corrosion, Ionization, Radioactive Isotopes
Atomic Number
874
3
117
👆🏻
Electron Configuration
[Rn] 7s1
[He] 2s2
Crystal Structure
Body Centered Cubic (BCC)
Hexagonal Close Packed (HCP)
Crystal Lattice
Atom
Number of Protons
874
3
117
👆🏻
Number of Neutrons
1365
4
285
👆🏻
Number of Electrons
874
3
117
👆🏻
Radius of an Atom
Atomic Radius
348.00 pm112.00 pm
0
348
👆🏻
Covalent Radius
260.00 pm96.00 pm
0
260
👆🏻
Van der Waals Radius
348.00 pm153.00 pm
0
348
👆🏻
Atomic Weight
223.00 amu9.01 amu
6.94
294
👆🏻
Atomic Volume
71.00 cm3/mol5.00 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
8.00 (-eV)82.00 (-eV)
0
392.42
👆🏻
Lattice Constant
440.00 pm228.58 pm
0
891.25
👆🏻
Lattice Angles
-
π/2, π/2, π/2
Lattice C/A Ratio
1.561.57
0.423
1.9
👆🏻
Density
Density At Room Temperature
1.87 g/cm31.85 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
1.87 g/cm31.69 g/cm3
0.512
41
👆🏻
Tensile Strength
50.00 MPa287.00 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
0.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
3.60 GPa132.00 GPa
1.3
222
👆🏻
Bulk Modulus
6.00 GPa130.00 GPa
0
462
👆🏻
Young's Modulus
0.00 GPa287.00 GPa
0
528
👆🏻
Poisson Ratio
0.440.03
0.032
0.47
👆🏻
Other Mechanical Properties
-
-
Magnetic Characteristics
Specific Gravity
0.871.85
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Diamagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
Poor Conductor
Semiconductor
Resistivity
3.00 nΩ·m36.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.03 106/cm Ω0.31 106/cm Ω
0
0.63
👆🏻
Electron Affinity
0.70 kJ/mol0.00 kJ/mol
0
222.8
👆🏻
Specific Heat
0.15 J/(kg K)1.82 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
27.00 J/mol·K16.44 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
15.00 W/m·K200.00 W/m·K
0
429
👆🏻
Critical Temperature
300.00 K1,551.00 K
26.3
3695
👆🏻
Thermal Expansion
18.90 µm/(m·K)11.30 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
67.00 kJ/mol294.70 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
2.30 kJ/mol11.72 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
71.00 kJ/mol326.40 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
42.00 J/mol.K9.50 J/mol.K
9.5
198.1
👆🏻