Symbol
Ra
Rb
Group Number
21
0
17
👆🏻
Period Number
75
2
7
👆🏻
Block
s block
s block
Element Family
Alkaline Earth
Alkali
CAS Number
74401447440177
7429905
54386242
👆🏻
Space Group Name
Im_ 3m
Im_ 3m
Space Group Number
229.00229.00
11
276
👆🏻
Interesting Facts
- Radium metal is the heaviest metal of Alkaline earth metals column.
- Radium metal is highly radioactive and does not have any stable isotopes.
- Rubidium metal is 16th most common element found in the earth crust.
- Rubidium metal also found in minerals as well as seawater.
Sources
Mining, Ores of metals
Obtained from Lithium Production.
History
Who Discovered
-
Robert Bunsen and Gustav Kirchhoff
Discovery
In 1898
In 1861
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
22
👆🏻
Abundance In Earth's Crust
0.00 %0.01 %
1E-37
8.1
👆🏻
Abundance In Oceans
0.00 %0.00 %
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- It is a highly radioactive metal; and sometime Radium-223 is used to treat prostate cancer.
-
It is used in luminous paints.
- Rubidium's main application is in the glass manufacturing.
- Rubidium can very easily get ionized and hence it is used for ion engines, but it is still less efficient than that of Caesium.
Industrial Uses
-
-
Medical Uses
Pharmaceutical Industry
-
Other Uses
-
Alloys, Research Purposes
Biological Properties
Toxicity
Highly Toxic
Non Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-32.49 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.00 p.p.m.5.00 p.p.m.
0
170000
👆🏻
Melting Point
700.00 °C38.89 °C
-38.83
3410
👆🏻
Boiling Point
1,737.00 °C688.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery White
Grayish White
Luster
Metallic
-
Hardness
Mohs Hardness
1.000.30
0.2
8.5
👆🏻
Brinell Hardness
700.00 MPa0.22 MPa
0.14
3490
👆🏻
Vickers Hardness
140.00 MPa0.22 MPa
0
3920
👆🏻
Speed of Sound
3,150.00 m/s1,300.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.001.54
0.155
3.41
👆🏻
Reflectivity
83.00 %52.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Ra
Rb
Isotopes
Known Isotopes
3329
0
38
👆🏻
Electronegativity
Pauling Electronegativity
0.900.82
0
2.6
👆🏻
Sanderson Electronegativity
0.890.31
0.22
2.56
👆🏻
Allred Rochow Electronegativity
0.970.89
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
0.920.69
0.62
2.48
👆🏻
Allen Electronegativity
0.890.71
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
3.103.18
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
509.30 kJ/mol403.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
979.00 kJ/mol2,633.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
509.30 kJ/mol3,860.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
5,093.00 kJ/mol5,080.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,090.00 kJ/mol6,850.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,090.00 kJ/mol8,140.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,090.00 kJ/mol9,570.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,090.00 kJ/mol13,120.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,090.00 kJ/mol14,500.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,090.00 kJ/mol26,740.00 kJ/mol
392
144300
👆🏻
11th Energy Level
5,090.00 kJ/mol4,030.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,090.00 kJ/mol4,030.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,090.00 kJ/mol4,030.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,090.00 kJ/mol4,030.00 kJ/mol
380
86450
👆🏻
15th Energy Level
50,900.00 kJ/mol40,300.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
50,900.00 kJ/mol40,300.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
509.30 kJ/mol403.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,090.00 kJ/mol4,030.00 kJ/mol
0
134810
👆🏻
19th Energy Level
509.30 kJ/mol403.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
509.00 kJ/mol403.00 kJ/mol
0
171200
👆🏻
21st Energy Level
509.30 kJ/mol403.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
509.00 kJ/mol403.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
509.30 kJ/mol403.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
509.30 kJ/mol403.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
509.00 kJ/mol403.00 kJ/mol
0
121900
👆🏻
26th Energy Level
509.30 kJ/mol403.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
509.30 kJ/mol403.00 kJ/mol
0
133800
👆🏻
28th Energy Level
509.30 kJ/mol403.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
509.30 kJ/mol403.00 kJ/mol
0
148100
👆🏻
30th Energy Level
509.00 kJ/mol403.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
4.22 g/amp-hr3.19 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.30 eV2.16 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
Atomic Number
8837
3
117
👆🏻
Electron Configuration
[Rn] 7s2
[Kr] 5s1
Crystal Structure
Body Centered Cubic (BCC)
Body Centered Cubic (BCC)
Crystal Lattice
Atom
Number of Protons
8837
3
117
👆🏻
Number of Neutrons
13848
4
285
👆🏻
Number of Electrons
8837
3
117
👆🏻
Radius of an Atom
Atomic Radius
215.00 pm248.00 pm
0
348
👆🏻
Covalent Radius
221.00 pm220.00 pm
0
260
👆🏻
Van der Waals Radius
283.00 pm303.00 pm
0
348
👆🏻
Atomic Weight
226.00 amu85.47 amu
6.94
294
👆🏻
Atomic Volume
45.20 cm3/mol55.90 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
20.10 (-eV)9.47 (-eV)
0
392.42
👆🏻
Lattice Constant
514.80 pm558.50 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
1.571.59
0.423
1.9
👆🏻
Density
Density At Room Temperature
5.50 g/cm31.53 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
5.50 g/cm31.46 g/cm3
0.512
41
👆🏻
Tensile Strength
40.00 MPa30.00 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
25.00 GPa2.50 GPa
1.3
222
👆🏻
Bulk Modulus
43.00 GPa2.50 GPa
0
462
👆🏻
Young's Modulus
83.00 GPa2.40 GPa
0
528
👆🏻
Poisson Ratio
0.310.37
0.032
0.47
👆🏻
Other Mechanical Properties
-
Ductile
Magnetic Characteristics
Specific Gravity
5.001.53
0.53
4500
👆🏻
Magnetic Ordering
Nonmagnetic
Paramagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
-
Conductor
Resistivity
100.00 nΩ·m128.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.00 106/cm Ω0.08 106/cm Ω
0
0.63
👆🏻
Electron Affinity
0.90 kJ/mol46.90 kJ/mol
0
222.8
👆🏻
Specific Heat
0.12 J/(kg K)0.36 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
20.05 J/mol·K31.06 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
18.60 W/m·K58.20 W/m·K
0
429
👆🏻
Critical Temperature
973.00 K2,093.00 K
26.3
3695
👆🏻
Thermal Expansion
8.50 µm/(m·K)90.00 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
113.00 kJ/mol69.20 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
8.60 kJ/mol2.19 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
163.00 kJ/mol82.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
71.00 J/mol.K76.80 J/mol.K
9.5
198.1
👆🏻