Cadmium                                                                                                

NAME:Cadmium                                                      GROUP IN THE PERIODIC TABLE : 12  

SYMBOL:Cd                                                           GROUP NAME:(none)

ATOMIC NUMBER:48                                            PERIOD IN THE TABLE:5

ATOMIC WEIGHT:112.411(8) see note g                BLOCK IN PERIODIC TABLE:d-block

STANDART STATE:Solid at 298 K                         COLOUR:silvery grey metallic

CAS REGISTRY ID:7440-43-9                                CLASSIFICATION:metalic

Nuclear fission

Cadmium is used as a barrier to control neutrons in nuclear fision. The pressurized water reactor designed by

Westinghouse Electric Company uses an alloy consisting of 80% silver, 15% indium, and 5% cadmium. 

Affected Organ Systems

 Cardiovascular (Heart and Blood Vessels), Developmental (effects during periods when organs are developing) , Gastrointestinal (Digestive), Neurological (Nervous System), Renal (Urinary System or Kidneys), Reproductive (Producing Children), Respiratory (From the Nose to the Lungs)

Discovered

Cadmium was discovered by Friedrich Strohmeyer (DE) in 1817. The origin of the name comes from the Latin word cadmia meaning calamine (zinc carbonate, ZnCO3), or from the Greek word kadmeia with the same meaning. It is a soft, malleable, blue-white metal that tarnishes in air, soluble in acids, insoluble in alkalis. Boiling cadmium gives off a weird, yellow-coloured vapour that is poisonous.

Phisical properties

Density / g dm^-3:8650 (293 K)

 7996 (m.p.)

Molar volume / cm³mol^-1:13.00 (293 K)

 14.06 (m.p.)

Electrical resistivity / μΩcm:6.83 (20 °C)

Thermal Properties

Thermal conductivity / W m^-1K^-1:96.8

Melting point / °C:312.07

Boiling point / °C:767

Heat of fusion / kJ mol^-1:6.11

Heat of vaporization / kJ mol^-1:100

Heat of atomization / kJ mol^-1:112.05

Abundanze of elements

in the atmosphere / ppm:-

in the Earth's crust / ppm:0.098

in the oceans / ppm:0.0001

Uses of cadmium

Cadmium is widely used in electronic items.
It is mostly used in the form of cadmium sulfide,which is a photosensitive material. It is used in blck and white television phosphors.
Cadmium is used in electroplating,which is the process of coating metal by making of an electrical current.
Most cadmium used in this country is obtained
as a by-product (formed while making
something else) from smelting (melting) zinc,
lead, or copper ores. The cadmium by-product
is mostly used in metal plating and to make
pigments, batteries, and plastics.

Cadmium oxide

Is an inorganic compound with the formula CdO . It is one of the main precursors to other cadmium compounds. It crystallizes in a cubic rocksalt lattice like sodium chloride , with octahedral  cation  and anion centers.  It occurs naturally as the rare mineral monteponite. Cadmium oxide can be found as a colorless amorphous powder or as brown or red crystals Cadmium oxide is an n-type semiconductor  with a band gap of 2.16 eV at room temperature.

Cadmium oxide

Cadmium sulfate

Is the name of a series of related inorganic compounds with the formula CdSO₄.xH₂O. The most common form is the monohydrate CdSO₄.H₂O, but two other forms are known CdSO₄.8/3H₂O and the anhydrous  salt (CdSO₄). All salts are colourless and highly soluble in water.

                           


Cadmium chloride

Is a white crystalline compound of cadmium and chlorine , with the formula CdCl₂. It is a higroscopy  solid that is highly soluble in water and slightly soluble in alcohol.



Occurrence

Cadmium occurs naturally in zinc, in lead and copper ores, in coal and other fossil fuels, in 
shales and is released during volcanic action. These deposits can serve as sources to ground and 
surface waters, especially when in contact with low total dissolved solids (TDS) and acidic
waters.

Cadmium is found in drinking water supplies as a result of deterioration of galvanized plumbing, 

along with industrial waste contamination, or surface water contamination by certain fertilizers...

Although it is possible for trace cadmium to be chelated or sequestered as with any metal, it will
generally be found in the dissolved ionic form.



Treatment Alternatives


In the ionic form in water, cadmium may be reduced by standard, strong acid cation resin 
regenerated with sodium chloride (NaCl) or suitable resin regeneration substitutes. Cadmium is
held more strongly than magnesium but less strongly than calcium. Therefore, care should be
taken to avoid operating past the hardness exhaustion 


How can you be exposed to cadmium?



You can be exposed to cadmium in the work
place by breathing cadmium-contaminated air.
If you work for a battery manufacturer or work
in metal soldering or welding, then workplace
exposure to cadmium may be greater.