Appearance and Characteristics
Harmful effects:
Cadmium and its compounds are highly toxic.
Characteristics:
Cadmium is a soft, malleable, ductile, bluish-white metal, which is easily cut with a knife. It is an excellent electrical conductor and shows good resistance to corrosion and attack by chemicals.
It is similar in many respects to zinc in its chemical properties.
Cadmium tarnishes in air and is soluble in acids but not in alkalis.
The metal burns in air to form brown cadmium oxide (CdO).
Uses of Cadmium
Cadmium’s major use is in batteries (especially rechargeable nickel-cadmium, NiCad, batteries).
As a result of its low coefficient of friction and its high fatigue resistance, cadmium is used in alloys for bearings. Cadmium is used in low melting alloys and is a component of many kinds of solder. It is also is used in electroplating.
Compounds containing cadmium are used in black and white television phosphors, and in the blue and green phosphors for color television picture tubes. Cadmium sulfide is used as a yellow pigment, and cadmium selenide is used as a red pigment, often called cadmium red.
Cadmium and tellurium can be compounded into CdTe thin-film photovoltaic modules whose physical characteristics are ideal for solar cell production. They are relatively low cost and have an almost perfect bandgap for solar energy harvesting.