Aug 13 2013
Topics Covered
Introduction
Chemical Properties
Physical Properties
Mechanical Properties
Thermal Properties
Applications
Introduction
Cadmium is a soft, bluish white metal that can be easily cut with a knife. Its chemical symbol is Cd and its atomic number is 48. It has similar characteristics to zinc and mercury and it tarnishes when exposed to air. It is soluble in acids but insoluble in alkalis. Cadmium belongs to the d-block, period 5 of the periodic table.
Canada, USA, Mexico and Australia are leading producers of cadmium.
Chemical Properties
The chemical properties of cadmium are provided in the table below:
Chemical Data |
CAS number |
7440-43-9 |
Thermal neutron cross section |
2.4 barns/atom |
Electrode potential |
-0.403 V |
Ionic radius |
0.970 Å |
Electro negativity |
1.69 |
X-ray absorption edge |
0.46408 Å |
Electrochemical equivalent |
2.09 g/A/h |
Physical Properties
The following table discusses the physical properties of cadmium.
Properties |
Metric |
Imperial |
Density |
8.64 g/cm3 |
0.312 lb/in3 |
Melting point |
321 °C |
610 °F |
Boiling point |
767°C |
1413°F |
Mechanical Properties
The mechanical properties of cadmium are tabulated below.
Properties |
Metric |
Imperial |
Tensile Strength |
75 MPa |
10900 psi |
Modulus of elasticity |
55.2 GPa |
8010 ksi |
Shear modulus |
19.2 GPa |
2780 ksi |
Hardness, Brinell |
16-24 |
16-24 |
Hardness, Vickers |
22 |
22 |
Poissons Ratio |
0.33 |
0.33 |
Thermal Properties
The thermal properties of cadmium are tabulated below.
Properties |
Metric |
Imperial |
Thermal expansion co-efficient (@20-100°C/68-212°F) |
30.0 µm/m°C |
16.7 µin/in°F |
Thermal conductivity |
92.0 W/mK |
638 BTU in/hr.ft².°F |
Applications
The following are the application areas of cadmium:
-
Making of nickel-cadmium batteries
-
Pigments, coatings and plating
-
Stabilizers in manufacture of plastics
-
Electroplating of steel
-
Nuclear reactors.
Cadmium compounds are used as black and white television phosphors, photoconductive surface in photocopier drums, paint pigments and in PVC.