Periodic table
A periodic table, also known as Table of Elements or elemental table, was a means of grouping chemical elements. Multiple periodic tables were known to the Federation, though elements unknown to any of them still existed. () Using the table, many elements shared a common atomic weight or symbol, and some even have multiple atomic weights or symbols and are listed twice.

Benny Russell had a periodic table on the wall of his kitchen in 1953. ()

On October 23, 2032, Lieutenant John Kelly recorded that after analyzing the contents of a graviton ellipse it would be necessary to make room on the periodic table. ()

In 2269, Spock stated that the matter-energy cloud had "elements not known in our periodic tables". ()

A Table of Elements was seen in a classroom aboard the  () and also in the classroom on Deep Space 9's Promenade. ()

In 3189, Ensign Sylvia Tilly discovered minerals at a settlement on a planet which were not on the elemental table. ()

Table of Elements

By atomic weight

Background information 

This table appeared in . It contains many in-jokes and errors, and is missing several key elements. Elements are also sorted by "atomic weight," and the atomic weights of the known elements differ from their actual atomic weights.  It is also interesting to note that the size of the atom itself (as seen in the okudagram of the Table of Elements) does not affect the atomic weight. This can be seen with the element poi, the heaviest element, and that its physical atomic size is much smaller than that of the element hawkeye, which is much lighter in terms of atomic weight.

The table from "Rascals" was later used for the classroom scenes on . However, in at least one case, in the episode  (see image on right), the table had a different color code. It is unknown if this table was also labeled with different elements than those seen in "Rascals". Another version of the periodic table can be found in the Starfleet Medical Reference Manual which is devoid of the "in-jokes" found on the Next Generation version.   

This is the periodic table used today, sorted by atomic number (number of protons found in the nucleus for every atom of that element), with links to real-world elements mentioned in Star Trek:

External link
 

cs:Periodická tabulka
de:Periodensystem der Elemente
it:Tavola periodica
ja:周期表
nl:Periodiek systeem
pt:Tabela periódica
Chemistry
Elements