Search: Oxygen, England
For the last few days there have been many reports of damage to car oxygen sensors in England's south east. This seems to have been cause by faulty fuel supplied by some supermarker chains, including Tesco and Morrison's. Initial reports suggested the fuel was up to standard but one wonders if this is a consequence of not applying the correct tests. Expecially now that reports are emerging (for instance from The BBC) that indeed there is a contamination arising from silcon, probably from silcone contaminants. Silicones are used in diesel but damage high-tech petrol engines.
The silicones were probably introduced inadvertantly at storage rather than at the refinery stage.
This is going to get expensive for someone as it sounds as though thousands of cars have been affected.
It is suggested that poisoning by polonium-210 may have caused the death of Alexander Litvinenko, said to be a former Russian spy, in November 2006. Following his death at the end of November 2006, traces of polonium were found at several places he had visited before becoming ill. Before his death it was thought that thallium, or even radiothallium, might have been the cause of his illness. At the time of writing it is not clear who killed him, but not surprisingly the Russians deny it. Polonium-210 decays through the emission of α-particles and these emissions are noramlly easy to stop, but they are very dangerous if the polonium is inside the body.
Polonium is radioactive and present only in extremely low abundances in the environment. It is quite metallic in nature despite its location beneath oxygen in the periodic table. It is made in very small quantities through a nuclear reaction of bismuth. Neutron irradiation of 209bismuth (atomic number 83) gives 210polonium (atomic number 84).
209Bi + 1n → 210Po + e-
Polonium-210, 210Po, transmutes into the lead isotope 206Pb by the emission of an α-particle. The half life for this process is just over 138 days meaning that after 138 days one-half of the original 210Po has disappeared and after 2 times 138 days 3/4 has gone.
21084Po → 20682Pb + 42He
The short half life of polonium-210 and the heat generated with the above radioactive decay means that polonium metal generates considerable heat (141 W), meaning that the metal and its compounds self-heat. This is a useful property and polonium can be used as a small heat source (if expensive!). It can be used in space satellites for this purpose and is especially desirable as there are no moving parts. It was also used in the lunar rovers to keep internal parts warm during the frigid lunar nights.
Polonium metal is unique in that it is the only element whose structure (known as the α-form) is a simple cubic array of atoms in which each atom is surrounded by six other polonium atoms. On gentle warming to 36°C, this converts into a second form known as the β-form.
Polonium dissolves in acids to form pink hydrated Po(II), presumably as[Po(OH2)6]2+. This seems to oxidize to yellow Po(IV) species perhaps as a consequence of oxidizing agents produced through the α-particle induced decay of water. The polonium(II) oxide PoO is known but this oxidizes easily to the Po(IV) oxide PoO2.
There are few crystallographically characterised polonium compounds largely because not many researchers work with polonium and the difficulties associated with characterising such radioactive compounds. The 14-electron polonium(IV) anion [PoI6]2– is strictly octahedral meaning the lone pair is sterochemically inactive.
Sequel to an Essay on the Constitution of the Atmosphere, Published in the Philosophical Transactions for 1826; With Some Account of the Sulphurets of Lime
The complete archive of the Royal Society journals, including some of the most significant scientific papers ever published since 1665, is to be made freely available electronically for the first time until 2007.
The archive contains seminal research papers including accounts of Michael Faraday's groundbreaking series of electrical experiments, Isaac Newton's invention of the reflecting telescope, and the first research paper published by Stephen Hawking.
The Society's online collection, which until now only extended back to 1997, contains every paper published in the Royal Society journals from the first ever peer-reviewed scientific journal, Philosophical Transactions in 1665, to the most recent addition, Interface.
You can register for free. So now, for a time at least, you can read free of charge some extraordinary historical documents. Here are a few examples:
- On the Constitution of the Atmosphere by John Dalton
- On the Action of Radium Emanations on Diamond by William Crookes
- The Separation of the Most Volatile Gases from Air without Liquefaction by James Dewar
- On the Compressibilities of Oxygen, Hydrogen, Nitrogen, and Carbonic Oxide between One Atmosphere and Half an Atmosphere of Pressure, and on the Atomic Weights of the Elements Concerned.--Preliminary Notice by Lord Rayleigh
Note: this facility seems to have been withdrawn?