The road system in Zambia is extremely simple. There are only a few major roads, and Lusaka on the road map is defined simply as a crossroads from which spring the 'Great North Road', the 'Great East Road', the 'Kafue Road' heading southerly, and the 'Mumbwa Road' heading West. I've followed the Great North Road almost as far as it reaches, straight up into the Northern Province, and turned off to the NorthWest reaching the town of Kasama. From here the road deteriorates markedly and is badly potholed. The last 250 km takes one to a T-junction. 5 km to the right is the town of Mbala. 25 km to the left however is my destination. Following this, the road drops quite swiftly through a thousand metres as you drop into the Rift Valley. Surrounded by the heights of the Zambian plateau is Lake Tanganyika. My road lies parallel to the valley and the lake and meets the shores at a small dusty down called Mpulungu, generally pronounced 'poolungoo', and we're 1140 km North of Lusaka at Zambia's only port.

This road just carries the port traffic from the once weekly ferry - the SS Liembe which you'll be familiar with if you saw the Hepburn/Bogart film 'African Queen'. Like most of the roads, its falling apart, though slightly better than the Kasama - Mbala road I've just left.

I'm delighted to announce that WebElements has collaborated with Theodore Gray to produce a new glossy laminated periodic table poster showing his fantastic photographs of the elements. The style of the poster is such that it pairs nicely with our existing periodic table poster. You can order it now from our online shop

Thomas Kuhn conceived over a half century ago that science should be distinguished into revolutionary periods separated by normal science. Normal science fills in the details while the rare revolutions replace one theoretical framework with a better paradigm. As a science develops, broad revolutions are followed by revolutions which make less sweeping changes. Our knowledge of elements and periodic charts seems to be in a period of normal science. And if revolutions occur in that part of chemistry, they are likely to be rather narrow in scope.

But a revolution may be about to change the way we learn chemistry. Major revolutions in education have been widely separated in time. Much from the Lyceum of Aristotle remains in today's schools. But the Internet has introduced a new medium much as Johannes Gutenberg advanced the printed medium in the 15th Century. The textbook and printed documents had a dramatic change on education and the way knowledge and understanding was transmitted from one generation to the next. Most of the pieces for another revolution are in place. Google has provided a ...

Polonium has no biological role and any sample used to kill the former KGB spy must have come from either a research laboratory or nuclear facility. It is found in uranium ores but at miniscule levels 0.00000001%. So small that the Curie's were awarded the Nobel prize for their superhuman effort to extract it. Could a terrorist smuggle Polonium into this country or is there a human leak at a UK Defence Establishment? Gramme quantities of polonium-210 are synthesized from bismuth in nuclear reactors. Carrying quantities of polonium is difficult because of the high temperature from radioactive decay [500oC] and the emission of deadly alpha particles. These radioactive particles are most dangerous when ingested. They pick up electrons from cells in the body and escape as helium gas. Polonium-210 has a relatively short half life [138 days] so the 'evidence' diminishes constantly with time. Also Polonium is fairly volatile and will evaporate if not kept in a sealed container. Polonium is one of the deadliest known substances and is believed to be a trillion more times toxic than HCN weight for weight.

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.

I'm slowly expanding some of the functionality on the WebElements periodic table site and we now have the bare bones of a news and forums site here (the current URL will switch to the main WebElements site in a
while). This part of the site will also house chemistry information pages in a "book " format (this will also be open to contributors in a while) and some other features.

The system I am using does allow individual users to post their own blogs and it seems to me that some of you have something to say. Chemists don't seem to be natural bloggers, however, this is an offer for some of you chemists out there to have your own blog on one of the highest profile chemistry sites around.

HEFCE to provide an additional £75 million to support very high cost and vulnerable science subjects

The Higher Education Funding Council for England is to provide £75 million in additional funding to support very high cost science subjects, which are strategically important to the UK economy and society but vulnerable because of relatively low student demand.

The funding over three years from 2007-08 will support chemistry; physics; chemical engineering; and mineral, metallurgy and materials engineering - to help maintain provision in these subjects in universities and colleges while demand from students grows.

Bone tissue contains a massive mineral phase and is unique from other tissue in the body. As a result of this, bone requires a different type of protein treatment, which has significant side effects to the rest of the body. Therefore, any treatment must be delivered specifically to bone and not target other tissues.

Biphosphonates are a class of material that have a strong affinity for bone matter. Although other molecules can also be used, Biphosphonates are thought to have more flexibility for use in bone delivery systems. These molecules can be linked to protein molecules to ensure delivery only to bone tissues. The target efficiency can be increased by attaching more phosphate molecules to each of the protein chains. Earlier studies have shown that complexes of Biphosphonate molecules show no decrease in bone seeking capabilities. Another advantage of this type of treatment is that the potency will increase without an increase in the dosage.

Brazil nuts have been promoted as a supplement to a healthy diet since the late 1970’s. This is due to their unusually high selenium content, an essential trace element known to be a powerful antioxidant and to reduce the likelihood of conditions such as heart disease and prostate cancer.

Recent research by Ryszard Lobinski and colleagues at the University of Pau and the Adour (France) has shown that the selenium compounds contained in Brazil nuts are seleno-peptides, and have developed a new method for their extraction, purification and characterisation. This has led to the discovery of 15 new seleno-peptides. Their research should help us to understand why Brazil nuts are so good at accumulating selenium.