Periodic Table

Periodic Table Quilt

Periodic Table QuiltPeriodic Table Quilt
Quite by chance I noticed that at Simon Fraser University in Canada members of staff in the Department got together to make a periodic table quilt. Looks to be about 6 feet across. I wonder if it will be updated for the latest elements?

If you go to the SFU site, click on any element to see that panel in more detail. Anyone else made a quilt like this?

FaceBook fame at last...

...as I see the WebElements A6 size periodic table card (laminated, naturally) is the logo for the FaceBook Group "The united nerd front" - A place for nerds to unite. (if you have a mini-periodic table you get gold card membership).

Periodic Table tattoo

Periodic Table tattooPeriodic Table tattoo
I'm interested in the periodic table - but not enough to get a periodic table tattoo! And here is one courtesy of o2b and writer Carl Zimmer. He has a collection of science tattoos for you to browse.

Spanish Post Office honours Mendeleev

Spanish Post Office honours MendeleevSpanish Post Office honours Mendeleev
This stamp commemorates the death of Mendeleev (February 1907), one of the lead figures responsible for the periodic table. Absolutely excellent choice of colours if I might say so! The stamp was sent to me by Prof Gabriel Pinto (Departamento de Ingeniería Química Industrial, ETSI Industriales, UPM, Madrid, Spain) and I quote from his web page:

"This stamp was launched on february 2, 2007, by Correos (Spanish Post Office). It is devoted to Chemistry with the periodic table of elements of Mendeleyéiev. It refers to the periodic classification of the chemistry elements proposed by Dmitri Ivanovich Mendeleyéiev in 1869. As he attempted to classify the elements according to their chemical properties, he noticed patterns that led him to postulate his Periodic Table which described elements according to both weight and valence and which, if arranged according to their atomic mass, exhibited an apparent periodicity of properties. Unlike other contributors to the table he predicted the properties of elements yet to be discovered and made an accurate prediction of the qualities of germanium, gallium, and scandium which came to fill in the empty boxes of his table. Mendeleyéiev (1834-1907) made other important contributions to chemistry such as studies on the expansion of liquids with heat, the invention of pyrocollodion, a kind of smokeless powder based on nitrocellulose and made important contributions to the determination of the nature of such indefinite compounds as solutions. He was the author of Principles of Chemistry, a classic on the subject and for a couple of years was responsible for the Department of Weights and Measures of Saint Petersburg."

New Periodic table photo poster

Periodic table photo posterPeriodic table photo poster
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

Polonium: did it kill Alexander Litvinenko?

Polonium metal structurePolonium metal structureIt 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 dioxidePolonium dioxidePolonium 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.

Polonium dichloridePolonium dichlorideThe Po(II) halides PoX2 (X = Cl, Br, I) are known (the chloride and bromide are particularly well characterised) while all the Po(IV) halides PoX4 (X = F, Cl, Br, I) are known.

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.

Do you want your own chemistry blog?

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.

This is an experiment and I want to offer the facility only to a few chemists just now. If you are interested please contact me via the contact form and tell me who you are, what you do (briefly!) and if it seems appropriate I'll set you up with your own blog. You shouldn't feel any pressure to write every day or even every week, just when you have something to say. All I ask is that you keep to chemistry, at least most of the time, and keep it polite.

Ig Nobel 2006 prize for Chemistry announced

The 2006 Ig Noble prize for chemistry has been announced and was awarded to Spanish researchers Antonio Mulet, José Javier Benedito and José Bon (University of Valencia), and Carmen Rosselló (University of Illes Balears), for their outstanding research: "Ultrasonic Velocity in Cheddar Cheese as Affected by Temperature." published in the Journal of Food Science.1

The Ig Noble prizes are administered by the publishers of the Annals of Improbable Research magazine. It's not always clear to me that the Chemistry Ig Noble prizes seem more related to other areas, and some non-chemistry prizes look as though the work was chemical, but never mind. For the record, here are a few of the more recent awards.

2005

Edward Cussler and Brian Gettelfinger (University of Minnesota and the University of Wisconsin), for their work that finally settled the longstanding scientific question: can people swim faster in syrup or in water? See "Will Humans Swim Faster or Slower in Syrup?".2

2004

The Coca-Cola Company of Great Britain, for using advanced technology to convert ordinary tap water into Dasani, a transparent form of water, which for "precautionary reasons" was withdrawn form the market in the UK (it seems the Dasani contained the carcinogenic bromate - the UK Food Standards Agency advice was that while Dasani contained illegal levels of bromate, it did not present an immediate risk to the public). See various press stories including:

  1. The Telegraph
  2. The Guardian

2003

Yukio Hirose of Kanazawa University in Japan, for his chemical investigation of a bronze statue in the city of Kanazawa that fails to attract pigeons.

2002

Theodore Gray of Wolfram Research (Champaign, Illinois, USA) for gathering elements of the periodic table and assembling them into a periodic table table.

New Periodic Table book by Eric Scerri

It's great to see a new book about the periodic table and this one is written by Eric Scerri, a world authority on the periodic table! Dr. Eric Scerri is a leading philosopher of science specializing in the history and philosophy of the periodic table. He is also the founder and editor in chief of the international journal Foundations of Chemistry and is a full-time lecturer at UCLA where he regularly teaches classes of 350 chemistry students as well as classes in history and philosophy of science. You can buy this book from our WebElements Amazon Store or our WebElements Amazon UK Store.

The Periodic Table: Its Story and Its Significance

The periodic table is one of the most potent icons in science. It lies at the core of chemistry and embodies the most fundamental principles of the field. The one definitive text on the development of the periodic table by van Spronsen (1969), has been out of print for a considerable time. The present book provides a successor to van Spronsen, but goes further in giving an evaluation of the extent to which modern physics has, or has not, explained the periodic system. The book is written in a lively style to appeal to experts and interested lay-persons alike.

The Periodic Table begins with an overview of the importance of the periodic table and of the elements and it examines the manner in which the term 'element' has been interpreted by chemists and philosophers. The book then turns to a systematic account of the early developments that led to the classification of the elements including the work of Lavoisier, Boyle and Dalton and Cannizzaro. The precursors to the periodic system, like Döbereiner and Gmelin, are discussed. In chapter 3 the discovery of the periodic system by six independent scientists is examined in detail.

Two chapters are devoted to the discoveries of Mendeleev, the leading discoverer, including his predictions of new elements and his accommodation of already existing elements. Chapters 6 and 7 consider the impact of physics including the discoveries of radioactivity and isotopy and successive theories of the electron including Bohr's quantum theoretical approach. Chapter 8 discusses the response to the new physical theories by chemists such as Lewis and Bury who were able to draw on detailed chemical knowledge to correct some of the early electronic configurations published by Bohr and others.

Chapter 9 provides a critical analysis of the extent to which modern quantum mechanics is, or is not, able to explain the periodic system from first principles. Finally, chapter 10 considers the way that the elements evolved following the Big Bang and in the interior of stars. The book closes with an examination of further chemical aspects including lesser known trends within the periodic system such as the knight's move relationship and secondary periodicity, as well at attempts to explain such trends.

China aims to extend the periodic table

China is expecting to complete work on the Heavy Ion Research Facility in Lanzhou (HIRFL) - Cooler Storage Ring (CSR) soon. Its director, Zhan Wenlong, of the Chinese Academy of Sciences, said "our target is to form new heavy elements and expand the Periodic Table" and "the building of large science facilities demonstrates not only our specific technological know-how, but also the prowess of our basic research".

The HIRFL-CSR, with a state investment of about 300 million yuan (37.5 U.S. dollars), includes a main ring, experimental ring, a radioactive separator and experimental detectors. "The building of large science facilities demonstrates not only our specific technological know-how, but also the prowess of our basic research," Zhan said. Chinese science strategists decided to build the HIRFL in the mid 1980s. The facility, which was put into operation in December 1988, was awarded the top national prize for technological advancement in 1992.

The CSR is the latest upgrade of the HIRFL, which has helped Chinese scientists to form two new heavy-nuclear elements.

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Copyright 1993-2011 Mark Winter [The University of Sheffield and WebElements Ltd, UK]. All rights reserved.