Cadmium

Element Name: Cadmium
Atomic Number: 48
Atomic Mass: 112.411
Atomic Symbol: Cd
Melting Point: 321.07° C
Boiling Point: 767° C

Cadmium is a highly toxic metal that is a neighbor to zinc and mercury. It is blue-silver and quite soft, able of being cut with a knife. It is similar to zinc such that it’s malleable, ductile, resistant to corrosion, and a good conductor of electricity. Cadmium gets its name from “cadmia”, the Greek for calamine. Both of these things are named after the Greek character Cadmus, the found of Thebes. Cadmium is found in natural isotopes, two of which are radioactive, and three of which are predicted to decay. There are 34 isotopes of cadmium total.

Interesting Facts:

Friedrich Stromeyer discovered cadmium in 1817 after a pharmacy had been mistakenly selling a zinc carbonate tainted by cadmium as zinc oxide. Cadmium used to be used in cathode ray tubes to produce black, green, and blue colors in color TVs. The length of the Angstrom was once defined with respect to cadmium’s red spectral line. Cadmium poisoning, while not very common, is quite harmful to humans. In the first half of the 1900s, a mining company in Japan spilled cadmium with a few other heavy metals into a river used for rice farming. The rice readily absorbed the cadmium and caused many painful health complications, giving it the name “itai-itai byo” (It hurts-it hurts disease). Smoking is a common source of Cadmium, and those who smoke have 4-5 times higher blood cadmium levels than non-smokers. People with mineral deficiencies and post-menopause women are vulnerable to cadmium poisoning. In 2010 McDonald’s recalled 12 million “Shrek Forever After 3D” cups because of concerns of unsafe cadmium levels.

Sources:

Metallic cadmium can be found in very few places in the world, notably the Vilyuy River basin in Siberia. Cadmium is also scarcely found in minerals, and the only mineral with appreciable amounts of cadmium is Greenockite. Rather, cadmium is usually found in small amounts when purifying zinc, copper, and lead. For every ton of zinc processed around 6.5 pounds of cadmium is produced. Cadmium is very rare in the earth’s crust overall, and is only present in 150 parts per billion.

Industrial Uses:

Cadmium is mostly used in nickel-cadmium batteries. Despite being very toxic and generally restricted by the EU, cadmium electrodes are used in these rechargeable batteries. Cadmium is also used to plate certain aircraft parts which are crucial for the airplane’s safety and must not rust (such as the bolts holding the landing gear in place). In nuclear reactors cadmium is used as a neutron poison to regulate the reactivity of the fissionable material. Cadmium telluride is used as a film in solar panels since its absorption bands are an excellent fit for sunlight. In less intelligent uses of cadmium, cadmium sulfide (often called “Cadmium Yellow”) is a bright pigment used in art. It is still used today, but is often diluted and carries several precautions.

References:

“Facts About Cadmium.” Livescience. Livescience.com, 31 May 2013. Web. 26 July
2016.
“Cadmium.” Wikipedia. Wikimedia Foundation, n.d. Web. 26 July 2016.
“Cadmium Element Facts / Chemistry.” Chemicool. Chemicool.com, 16 Oct. 2012.
Web. 26 July 2016.
Gray, Theodore W., and Nick Mann. The Elements: A Visual Exploration of Every
Known Atom in the Universe. New York: Black Dog & Leventhal, 2009. Print.