Rubidium Cadmium Comparison
Periodic Table
Symbol
Rb
Cd
Group Number
1
17
12
6
Period Number
5
5
Block
s block
d block
Element Family
Alkali
Transition Metal
CAS Number
7440177
99+
7440439
99+
Space Group Name
Im_ 3m
P63/mmc
Space Group Number
229.00
1
194.00
5
Facts
Interesting Facts
- Rubidium metal is 16th most common element found in the earth crust.
- Rubidium metal also found in minerals as well as seawater.
- Naturally occurring minor elements include Cadmium.
- Cadmium is released into atmosphere to control volcanic eruption and forest fires.
- It is used for electroplating of Steel for corrosion resistance.
- It can absorb neutrons and used in nuclear reactor to control atomic fission.
Sources
Obtained from Lithium Production.
Found As a By-product, Found in Minerals, Mining
History
Who Discovered
Robert Bunsen and Gustav Kirchhoff
Karl Samuel Leberecht Hermann and Friedrich Stromeyer
Discovery
In 1861
In 1817
Abundance
Abundance In Universe
1 * 10-6 %
16
2 * 10-7 %
22
Abundance In Sun
~0.000003 %
17
~0.0000006 %
21
Abundance In Meteorites
0.00 %
19
0.00 %
31
Abundance In Earth's Crust
0.01 %
18
0.00 %
99+
Abundance In Oceans
0.00 %
7
0.00 %
28
Abundance In Humans
0.00 %
7
0.00 %
11
Uses
Uses & Benefits
- 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.
- It has very limited uses as it is a toxic metal and it can cause birth defects, cancer, etc.
- Almost 80% of Cadmium metal is used in Nickel cadmium Batteries and now it is getting replaced with nickel hydride.
Industrial Uses
NA
Aerospace Industry, Ammunition Industry, Chemical Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
NA
Other Uses
Alloys, Research Purposes
Alloys
Biological Properties
Toxicity
Non Toxic
Toxic
Present in Human Body
Yes
Yes
In Blood
2.49 Blood/mg dm-3
7
0.01 Blood/mg dm-3
24
In Bone
5.00 p.p.m.
13
1.80 p.p.m.
15
Physical Properties
Melting Point
38.89 °C
99+
320.90 °C
99+
Boiling Point
688.00 °C
99+
765.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Grayish White
Silvery Bluish-Gray
Luster
NA
Metallic
Hardness
Mohs Hardness
0.30
24
2.00
16
Brinell Hardness
0.22 MPa
99+
203.00 MPa
39
Speed of Sound
1,300.00 m/s
99+
2,310.00 m/s
39
Optical Properties
Reflectivity
Not Available
67.00 %
11
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
Rb
Cd
Isotopes
Known Isotopes
29
10
34
5
Electronegativity
Pauling Electronegativity
0.82
99+
1.69
17
Sanderson Electronegativity
0.31
32
1.98
9
Allred Rochow Electronegativity
0.89
40
1.46
15
Mulliken-Jaffe Electronegativity
0.69
24
1.53
13
Allen Electronegativity
0.71
99+
1.52
27
Electropositivity
Pauling Electropositivity
3.18
3
2.31
37
Ionization Energies
1st Energy Level
403.00 kJ/mol
99+
867.80 kJ/mol
11
2nd Energy Level
2,633.00 kJ/mol
6
1,631.40 kJ/mol
32
3rd Energy Level
3,860.00 kJ/mol
11
3,616.00 kJ/mol
13
4th Energy Level
5,080.00 kJ/mol
18
Not Available
5th Energy Level
6,850.00 kJ/mol
19
Not Available
6th Energy Level
8,140.00 kJ/mol
20
Not Available
7th Energy level
9,570.00 kJ/mol
20
Not Available
8th Energy Level
13,120.00 kJ/mol
17
Not Available
9th Energy Level
14,500.00 kJ/mol
18
Not Available
10th Energy Level
26,740.00 kJ/mol
6
Not Available
Electrochemical Equivalent
3.19 g/amp-hr
14
2.10 g/amp-hr
27
Electron Work Function
2.16 eV
99+
4.22 eV
22
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
37
99+
48
99+
Electron Configuration
[Kr] 5s1
[Kr] 4d10 5s2
Crystal Structure
Body Centered Cubic (BCC)
Hexagonal Close Packed (HCP)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
HCP-Crystal-Structure-of-Cadmium.jpg#100
Atom
Number of Protons
37
99+
48
99+
Number of Neutrons
48
99+
64
99+
Number of Electrons
37
99+
48
99+
Radius of an Atom
Atomic Radius
248.00 pm
2
151.00 pm
32
Covalent Radius
220.00 pm
4
144.00 pm
40
Van der Waals Radius
303.00 pm
3
158.00 pm
99+
Atomic Weight
85.47 amu
99+
112.41 amu
99+
Atomic Volume
55.90 cm3/mol
2
13.10 cm3/mol
39
Adjacent Atomic Numbers
Valence Electron Potential
9.47 (-eV)
99+
30.00 (-eV)
99+
Lattice Constant
558.50 pm
10
297.94 pm
99+
Lattice Angles
π/2, π/2, π/2
π/2, π/2, 2 π/3
Lattice C/A Ratio
Not Available
1.89
1
Mechanical Properties
Density
Density At Room Temperature
1.53 g/cm3
99+
8.65 g/cm3
99+
Density When Liquid (at m.p.)
1.46 g/cm3
99+
8.00 g/cm3
28
Tensile Strength
Not Available
62.00 MPa
16
Viscosity
Not Available
Not Available
Vapor Pressure
Elasticity properties
Shear Modulus
Not Available
19.00 GPa
35
Bulk Modulus
2.50 GPa
99+
42.00 GPa
29
Young's Modulus
2.40 GPa
99+
50.00 GPa
36
Poisson Ratio
Not Available
0.30
14
Other Mechanical Properties
Ductile
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
1.53
99+
8.65
36
Magnetic Ordering
Paramagnetic
Diamagnetic
Electrical Properties
Electrical Property
Conductor
Semiconductor
Resistivity
128.00 nΩ·m
26
72.70 nΩ·m
36
Electrical Conductivity
0.08 106/cm Ω
24
0.14 106/cm Ω
15
Electron Affinity
46.90 kJ/mol
24
0.00 kJ/mol
40
Thermal Properties
Specific Heat
0.36 J/(kg K)
17
0.23 J/(kg K)
26
Molar Heat Capacity
31.06 J/mol·K
5
26.02 J/mol·K
32
Thermal Conductivity
58.20 W/m·K
26
96.60 W/m·K
16
Critical Temperature
2,093.00 K
4
Not Available
Thermal Expansion
90.00 µm/(m·K)
2
30.80 µm/(m·K)
10
Enthalpy
Enthalpy of Vaporization
69.20 kJ/mol
99+
100.00 kJ/mol
99+
Enthalpy of Fusion
2.19 kJ/mol
99+
6.19 kJ/mol
99+
Enthalpy of Atomization
82.00 kJ/mol
99+
113.00 kJ/mol
99+
Standard Molar Entropy
76.80 J/mol.K
5
51.80 J/mol.K
27
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