Mendeleev's predicted elements
Dmitri Mendeleev published a periodic table of the chemical elements in 1869 based on properties that appeared with some regularity as he laid out the elements from lightest to heaviest. When Mendeleev proposed his periodic table, he noted gaps in the table and predicted that as-then-unknown elements existed with properties appropriate to fill those gaps. He named them eka-boron, eka-aluminium and eka-silicon with atomic masses 44, 68 and 72 respectively.
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.