Symbol
Cd
  
Hg
  
Period Number
5
  
6
  
Block
d block
  
d block
  
Element Family
Transition Metal
  
Transition Metal
  
Space Group Name
P63/mmc
  
R_ 3m
  
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.
  
- At room temperature mercury is found in a liquid state.
- A coin of pound or rupees floats in mercury.
- Because of its low melting point and boiling point it is used in thermometers.
  
Sources
Found As a By-product, Found in Minerals, Mining
  
Mining, Ores of Minerals
  
History
  
  
Who Discovered
Karl Samuel Leberecht Hermann and Friedrich Stromeyer
  
Ancient Chinese and Indians
  
Discovery
In 1817
  
Before 2000 BCE
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~0.0000006 %
  
21
~-9999 %
  
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Abundance In Oceans
Not Available
  
Abundance In Humans
Not Available
  
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.
  
- It is a liquid metal at room temperature, but it is a toxic heavy metal and hence many uses of mercury are under review or phased out.
- It is manly used as a catalysts in chemical industry.
  
Industrial Uses
Aerospace Industry, Ammunition Industry, Chemical Industry, Electrical Industry, Electronic Industry
  
Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
Dentistry
  
Other Uses
Alloys
  
Alloys, Mirror Manufacturing, Pharmaceutical Industry
  
Biological Properties
  
  
Toxicity
Toxic
  
Highly Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
0.01 Blood/mg dm-3
  
24
0.01 Blood/mg dm-3
  
23
In Bone
1.80 p.p.m.
  
15
0.45 p.p.m.
  
19
Melting Point
Not Available
  
Appearance
  
  
Physical State
Solid
  
Liquid
  
Color
Silvery Bluish-Gray
  
Silver
  
Luster
Metallic
  
NA
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
Speed of Sound
2,310.00 m/s
  
39
1,451.40 m/s
  
99+
Optical Properties
  
  
Refractive Index
Not Available
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Cd
  
Hg
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
867.80 kJ/mol
  
11
1,007.10 kJ/mol
  
4
2nd Energy Level
1,631.40 kJ/mol
  
32
1,810.00 kJ/mol
  
20
3rd Energy Level
3,616.00 kJ/mol
  
13
3,300.00 kJ/mol
  
20
Electrochemical Equivalent
2.10 g/amp-hr
  
27
3.74 g/amp-hr
  
10
Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Flammability, Ionization, Solubility
  
Electron Configuration
[Kr] 4d10 5s2
  
[Xe] 4f14 5d10 6s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Rhombohedral (RHO)
  
Crystal Lattice
HCP-Crystal-Structure-of-Cadmium.jpg#100
  
RHO-Crystal-Structure-of-Mercury.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
112.41 amu
  
99+
Atomic Volume
13.10 cm3/mol
  
39
14.82 cm3/mol
  
35
Adjacent Atomic Numbers
  
  
Valence Electron Potential
30.00 (-eV)
  
99+
28.20 (-eV)
  
99+
Lattice Angles
π/2, π/2, 2 π/3
  
NA
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
8.65 g/cm3
  
99+
13.53 g/cm3
  
24
Density When Liquid (at m.p.)
Not Available
  
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile, Malleable
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Diamagnetic
  
Diamagnetic
  
Electrical Properties
  
  
Electrical Property
Semiconductor
  
Conductor
  
Electrical Conductivity
0.14 106/cm Ω
  
15
0.01 106/cm Ω
  
99+
Electron Affinity
0.00 kJ/mol
  
40
0.00 kJ/mol
  
40
Specific Heat
0.23 J/(kg K)
  
26
0.14 J/(kg K)
  
38
Molar Heat Capacity
26.02 J/mol·K
  
32
27.98 J/mol·K
  
13
Thermal Conductivity
96.60 W/m·K
  
16
8.30 W/m·K
  
99+
Critical Temperature
Not Available
  
Thermal Expansion
30.80 µm/(m·K)
  
10
60.40 µm/(m·K)
  
5
Enthalpy
  
  
Enthalpy of Vaporization
100.00 kJ/mol
  
99+
56.90 kJ/mol
  
99+
Enthalpy of Fusion
6.19 kJ/mol
  
99+
2.29 kJ/mol
  
99+
Enthalpy of Atomization
113.00 kJ/mol
  
99+
61.50 kJ/mol
  
99+
Standard Molar Entropy
51.80 J/mol.K
  
27
75.80 J/mol.K
  
6