beryllium and iodine
Both beryllium and iodine are naturally present in the atmosphere. However, some radioactive isotopes are formed in nuclear power plants and they enter the atmosphere. These are highly toxic and will cause serious health problems if inhaled or ingested in large amounts.
Chemicals prepared from beryllium and iodine have many uses. They are useful as a catalyst for reactions that produce alkyl and aromatic compounds, as well as being used in spectrophotometry.
BeI2 reacts with chlorine gas to form fluorides of both beryllium and iodine, which emit light and heat. It is also attacked by cyanogen, giving a white substance less volatile than the iodide, and when heated with water it produces a clear solution of beryllium reacting with cyanides.
Treatment of beryllium with sulfur to form a sulfide yields a material that is less flammable than the iodide, which decomposes easily with water. It may also be attacked by phosphorus to form a phosphide of beryllium, which is also less flammable than the iodide.
Beryllium is also known to be a component of some radionuclides, including Iodine 131. This isotope is a highly toxic and long-lived radionuclide that has been responsible for atmospheric testing of nuclear weapons since 1945 and is likely to continue to be harmful for decades and centuries to come.
In chemistry, beryllium is an important metal and its ions are commonly found in compounds with alkyl groups. It is frequently reacted with Grignard reagents and dialkylmercury to produce a variety of organic compounds. It can be precipitated in the solid state as beryllium chloride with acetoanilide or as a complex of beryllium with ammonium phosphate.