This website is an interactive periodic table with a comprehensive database of element properties, which can be searched and collated in novel and useful ways. Pictures of elements and compounds are being taken and collected into the database. Periodic table art, music and educational games are available. A huge listing of other periodic tables on the internet is on this website, sorted and annotated.
Nuclear chemistry buffs will find information on over 2600 isotopes of the elements. Radioactive decay can be illustrated for most unstable nuclides.
The main features of this site are listed on the main page, but here are the highlights:
A short history of the periodic table.
The rectangular periodic table is familiar to anybody who has ever been in a science laboratory or classroom. This ingenious functional grouping of the chemical elements was created by several European scientists in the decade of the 1860's. In 1863, a 44 year old French geologist, A. E. Béguyer de Chancourtois created a list of the elements arranged by increasing atomic weight. The list was wrapped around a cylinder so that several sets of similar elements lined up, creating the first geometric representation of the periodic law.
In England, 32 year old analytical chemist John A. R. Newlands was also wrapping the elements, noting that chemical groups repeated every eight elements. He named this the octave rule, and compared it to a musical scale. Some less observant members of the English Chemical Society considered this absurd, so his work was ignored for years.
Chemists Dmitrii I. Mendeleev, a Russian, and German Lothar Meyer were working independently in 1868 and 1869 on the arrangement of elements into seven columns, corresponding to various chemical and physical properties. Their tables were similar - they acknowledged each other's work - the differences are subtle but important: Meyer's table was an accurate (for the time) accounting of the known facts about each element, such as melting point and atomic volume. The table clearly showed the existence of periodic chemical families. In 1870 Meyer's table and description of the periodic law was published in Liebig's Annalen.
A year earlier however, the 35 year old Mendeleev presented a much bolder and scientifically useful table. His paper, On the Relation of the Properties to the Atomic Weights of the Elements, was enthusiastically received by the Russian Chemical Society. In it, the periodic relationship between chemical groups, that is, elements with a similar stoichiometry of reaction, is clearly illustrated. In a scientific triumph, gaps in the table accurately predicted undiscovered elements.
Although it is nearly 130 years old, Mendeleev's table differs little from the charts on the walls of laboratories today. The insight obtained in that productive decade resulted in a tool that furthers understanding and eases the use of chemistry in every laboratory in the world.
Books and other resources that were referenced for this site:
This site is made and maintained by Chris Heilman. No part of the site is an official publication of Phoenix College, or the Maricopa Community College District or represents any statement on the part of either entity.
The information in this site is taken from public records and is not tested for correctness. Additional errors may be introduced during handling. If you are doing calculations for reasons other than fun, please double check the data against a standard reference (such as some of those listed above.) Chris Heilman, Phoenix College and the Maricopa Community College District are not responsible for the correctness, accuracy or use of the data presented here.