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