Periodic table
The organization of the periodic table can be used to derive relationships between the various element properties, and also to predict chemical properties and behaviours of undiscovered or newly synthesized elements. Russian chemist Dmitri Mendeleev published the first recognizable periodic table in 1869, developed mainly to illustrate periodic trends of the then-known elements. He also predicted some properties of unidentified elements that were expected to fill gaps within the table. Most of his forecasts proved to be correct. Mendeleev's idea has been slowly expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain chemical behaviour. The modern periodic table now provides a useful framework for analyzing chemical reactions, and continues to be widely used in chemistry, nuclear physics and other sciences.
Rime table
The oldest known rhyme tables are a version of the "Yunjing" published with prefaces dated 1161 and 1203, and the "Qiyin lüe", which was included in the 1161 encyclopedia "Tongzhi". The two are very similar, and are believed to be derived from a single version pre-dating the Song dynasty. The tables were accompanied by a body of teachings known as "mēnfǎ" (), including rules for placing fanqie spellings that did not conform to the system within the tables.