Symbol
Cr
Rb
Group Number
61
0
17
👆🏻
Period Number
45
2
7
👆🏻
Block
d block
s block
Element Family
Transition Metal
Alkali
CAS Number
74404737440177
7429905
54386242
👆🏻
Space Group Name
Im_ 3m
Im_ 3m
Space Group Number
229.00229.00
11
276
👆🏻
Interesting Facts
- Chromium is highly reactive, hence it is not found free in nature.
- Ores of Chromites mineral are the major source of Chromium metal.
- Almost 90% leather tanning is done with the help of chromium.
- Rubidium metal is 16th most common element found in the earth crust.
- Rubidium metal also found in minerals as well as seawater.
Sources
Found in Minerals, Mining, Ores of metals, Ores of Minerals
Obtained from Lithium Production.
History
Who Discovered
Louis Nicolas Vauquelin
Robert Bunsen and Gustav Kirchhoff
Discovery
In Between 1797 - 1798
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
0.30 %0.00 %
0
22
👆🏻
Abundance In Earth's Crust
0.01 %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 used to harden the steel and produces a stainless steel and other various alloys.
- It is also used to give proper finish to polished mirrors. Its chromium plates are used in bathroom fittings.
- 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
Automobile Industry, Chemical Industry
-
Medical Uses
-
-
Other Uses
Alloys
Alloys, Research Purposes
Biological Properties
Toxicity
Highly Toxic
Non Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.11 Blood/mg dm-32.49 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.33 p.p.m.5.00 p.p.m.
0
170000
👆🏻
Melting Point
1,857.00 °C38.89 °C
-38.83
3410
👆🏻
Boiling Point
2,672.00 °C688.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silver
Grayish White
Luster
Metallic
-
Hardness
Mohs Hardness
8.500.30
0.2
8.5
👆🏻
Brinell Hardness
687.00 MPa0.22 MPa
0.14
3490
👆🏻
Vickers Hardness
1,060.00 MPa0.22 MPa
0
3920
👆🏻
Speed of Sound
5,940.00 m/s1,300.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
2.971.54
0.155
3.41
👆🏻
Reflectivity
70.00 %52.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Cr
Rb
Isotopes
Known Isotopes
2129
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.660.82
0
2.6
👆🏻
Sanderson Electronegativity
1.660.31
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.560.89
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.660.69
0.62
2.48
👆🏻
Allen Electronegativity
1.650.71
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.343.18
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
26,130.00 kJ/mol403.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
28,750.00 kJ/mol2,633.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
34,230.00 kJ/mol3,860.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
37,066.00 kJ/mol5,080.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
97,510.00 kJ/mol6,850.00 kJ/mol
392
97510
👆🏻
6th Energy Level
105,800.00 kJ/mol8,140.00 kJ/mol
1007
105800
👆🏻
7th Energy level
114,300.00 kJ/mol9,570.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
125,300.00 kJ/mol13,120.00 kJ/mol
730
125300
👆🏻
9th Energy Level
134,700.00 kJ/mol14,500.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
144,300.00 kJ/mol26,740.00 kJ/mol
392
144300
👆🏻
11th Energy Level
26,130.00 kJ/mol4,030.00 kJ/mol
392
169988
👆🏻
12th Energy Level
28,750.00 kJ/mol4,030.00 kJ/mol
0
189368
👆🏻
13th Energy Level
34,230.00 kJ/mol4,030.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
37,066.00 kJ/mol4,030.00 kJ/mol
380
86450
👆🏻
15th Energy Level
97,510.00 kJ/mol40,300.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
105,800.00 kJ/mol40,300.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
114,300.00 kJ/mol403.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
125,300.00 kJ/mol4,030.00 kJ/mol
0
134810
👆🏻
19th Energy Level
134,700.00 kJ/mol403.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
144,300.00 kJ/mol403.00 kJ/mol
0
171200
👆🏻
21st Energy Level
157,700.00 kJ/mol403.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
166,090.00 kJ/mol403.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
653.80 kJ/mol403.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
653.80 kJ/mol403.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
653.80 kJ/mol403.00 kJ/mol
0
121900
👆🏻
26th Energy Level
653.80 kJ/mol403.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
652.90 kJ/mol403.00 kJ/mol
0
133800
👆🏻
28th Energy Level
653.80 kJ/mol403.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
653.80 kJ/mol403.00 kJ/mol
0
148100
👆🏻
30th Energy Level
653.80 kJ/mol403.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
0.32 g/amp-hr3.19 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.50 eV2.16 eV
2.14
6
👆🏻
Other Chemical Properties
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
Atomic Number
2437
3
117
👆🏻
Electron Configuration
[Ar] 3d5 4s1
[Kr] 5s1
Crystal Structure
Body Centered Cubic (BCC)
Body Centered Cubic (BCC)
Crystal Lattice
Atom
Number of Protons
2437
3
117
👆🏻
Number of Neutrons
2848
4
285
👆🏻
Number of Electrons
2437
3
117
👆🏻
Radius of an Atom
Atomic Radius
128.00 pm248.00 pm
0
348
👆🏻
Covalent Radius
139.00 pm220.00 pm
0
260
👆🏻
Van der Waals Radius
200.00 pm303.00 pm
0
348
👆🏻
Atomic Weight
52.00 amu85.47 amu
6.94
294
👆🏻
Atomic Volume
7.23 cm3/mol55.90 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
170.00 (-eV)9.47 (-eV)
0
392.42
👆🏻
Lattice Constant
291.00 pm558.50 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
1.861.59
0.423
1.9
👆🏻
Density
Density At Room Temperature
7.19 g/cm31.53 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
6.30 g/cm31.46 g/cm3
0.512
41
👆🏻
Tensile Strength
689.00 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
774.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
115.00 GPa2.50 GPa
1.3
222
👆🏻
Bulk Modulus
160.00 GPa2.50 GPa
0
462
👆🏻
Young's Modulus
279.00 GPa2.40 GPa
0
528
👆🏻
Poisson Ratio
0.210.37
0.032
0.47
👆🏻
Other Mechanical Properties
-
Ductile
Magnetic Characteristics
Specific Gravity
7.191.53
0.53
4500
👆🏻
Magnetic Ordering
Antiferromagnetic
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
125.00 nΩ·m128.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.08 106/cm Ω0.08 106/cm Ω
0
0.63
👆🏻
Electron Affinity
64.30 kJ/mol46.90 kJ/mol
0
222.8
👆🏻
Specific Heat
0.45 J/(kg K)0.36 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
23.35 J/mol·K31.06 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
93.90 W/m·K58.20 W/m·K
0
429
👆🏻
Critical Temperature
1,907.00 K2,093.00 K
26.3
3695
👆🏻
Thermal Expansion
4.90 µm/(m·K)90.00 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
348.80 kJ/mol69.20 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
15.31 kJ/mol2.19 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
397.50 kJ/mol82.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
23.80 J/mol.K76.80 J/mol.K
9.5
198.1
👆🏻