Chemistry International Blank Image
Chemistry International Text Image Link to Chemistry International Blank Image Chemistry International Blank Image Chemistry International Blank Image
Chemistry International Blank Image
Chemistry International Blank Image
Chemistry International Text Image Link to Current Issue
Chemistry International Text Image Link to Past Issues
Chemistry International Text Image Link to Officer's Columns
Chemistry International Text Image Link to Features
Chemistry International Blank Image
Chemistry International Text Image Link to Up for Discussion
Chemistry International Text Image Link to IUPAC Wire
Chemistry International Text Image Link to Project Place
Chemistry International Text Image Link to imPACt
Chemistry International Text Image Link to Bookworm
Chemistry International Text Image Link to Internet Connections
Chemistry International Text Image Link to Conference Call
Chemistry International Text Image Link to Where 2B and Y
Chemistry International Text Image Link to Symposia
Chemistry International Text Image Link to CI Indexes
Chemistry International Text Image Link to CI Editor
Chemistry International Text Image Link to Search Function
Chemistry International Text Image Link to Information

 

Chemistry International Text Image Link to Previous Issue Chemistry International Text Image Link to Previous Page Chemistry International Text Image Link to This TOC Chemistry International Text Image Link to Next Page Chemistry International Text Image Link to Next Issue

Vol. 30 No. 3
May-June 2008

Stamps International |

See also www.iupac.org/publications/ci/indexes/stamps.html


Triads, Triads, Everywhere

Johann Wolfgang Döbereiner (1780-1849), a professor of chemistry at the University of Jena, was the first to recognize that several groups of three elements, such as lithium, sodium, and potassium, or chlorine, bromine, and iodine, had similar chemical properties. In addition, he noticed that the atomic weight of the middle element in these triads was roughly the average of those of the other two. These observations led to his Law of Triads (1829), which firmly established his reputation as a pioneer in the development of the modern periodic table some 40 years before Mendeleev’s masterpiece was published.

However, the stamp illustrated in this note, issued in East Germany (DDR) on 26 February 1980 to commemorate the 200th anniversary of Döbereiner’s birth (which was actually on 13 December 1780), does not mention his seminal contribution to the organization of the elements but features instead his “other” claim to fame. The stamp shows a schematic drawing of his renowned lighter, in which a stream of hydrogen gas, generated from zinc and sulfuric acid, spontaneously ignites upon contact with finely divided platinum. This novel chemical reaction received a lot of attention since it was first described by Döbereiner in the summer of 1823 and was swiftly reproduced by others. Within months the discovery was reported in multiple European scientific journals, which ushered in an era of interest in catalysis that continues to this day.

For a recent discussion of triads in the periodic table, see: Scerri, E. J. Chem. Educ. 2008, 85, 585-589.

Written by Daniel Rabinovich <[email protected]>.


Page last modified 5 June 2008.
Copyright © 2003-2008 International Union of Pure and Applied Chemistry.
Questions regarding the website, please contact [email protected]
Link to CI Home Page Link to IUPAC E-News Link to IUPAC Home Page