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Cadmium [Cd] locate me
CAS-ID: 7440-43-9
An: 48 N: 64
Am: 112.411 g/mol
Group No: 12
Group Name: Transition metals
Block: d-block  Period: 5
State: solid at 298 K
Colour: silvery grey metallic Classification: Metallic
Boiling Point: 1040K (767°C)
Melting Point: 594.22K (321.07°C)
Superconducting temperature: 0.517K (-272.633°C)
Density: 8.65g/cm3
Discovery Information
Who: Fredrich Stromeyer
When: 1817
Where: Germany
Name Origin
Greek: kadmeia (ancient name for calamine (ZnCO3)); Latin: cadmia.
 "Cadmium" in different languages.
Sources
Obtained as a by product of zinc refining. Occurs in rare ores such as Greenockite (CdS), the only mineral cadmium of any importance.
Annual production is around 14 thousand tons.
Abundance
 Universe: 0.002 ppm (by weight)
 Sun: 0.006 ppm (by weight)
 Carbonaceous meteorite: 0.45 ppm
 Earth's Crust: 0.11 ppm
 Seawater:
   Atlantic surface: 1.1 x 10-6 ppm
   Atlantic deep: 3.8 x 10-5 ppm
   Pacific surface: 1.1 x 10-6 ppm
   Pacific deep: 1 x 10-4 ppm
 Human:
   700 ppb by weight
   39 ppb by atoms
Uses
Used in nickel-cadmium batteries (about 75% of all cadmium is used in batteries), nuclear reactor regulator, bearing alloys, solder and red/yellow pigments.
Compounds containing cadmium are used in black and white television phosphors and also in the blue and green phosphors for colour television picture tubes.
Used in some semiconductors such as cadmium sulfide (CdS), cadmium selenide (CdSe), and cadmium telluride (CdTe), which can be used for light detection or solar cells. Mercury cadmium telluride (HgCdTe) is sensitive to infrared.
Cadmium forms various salts, with cadmium sulfide (CdS) being the most common. This sulfide is used as a yellow pigment. Cadmium selenide (CdSe) can be used as red pigment, commonly called cadmium red.
History
Cadmium (Latin cadmia, Greek kadmeia meaning "calamine") was discovered in Germany in 1817 by Friedrich Strohmeyer. Strohmeyer found the new element within an impurity in zinc carbonate (calamine) and for 100 years Germany remained the only important producer of the metal. The metal was named after the Latin word for calamine since the metal was found in this zinc compound. Strohmeyer noted that some impure samples of calamine changed colour when heated but pure calamine did not.
Even though cadmium and its compounds are highly toxic, the British Pharmaceutical Codex from 1907 states that cadmium iodide was used as a medicine to treat "enlarged joints, scrofulous glands, and chilblains".
Notes
Cadmium is a soft ductile metal that can easily be cut with a knife.
Hazards
Cadmium is extremely poisonous, even in low concentrations. Many cadmium compounds are believed to be carcinogenic.
Cadmium is harmful to aquatic organisms and water treatment plants.