It is an icon of natural science and hangs in most chemistry classrooms: the periodic table of elements, which is celebrating its 150th birthday this year. The tabular overview is closely linked to ...

Early periodic tables were incomplete, since many elements were unknown. Also, some elements were placed in groups with elements that were not similar to them. Mendeleev left gaps in his table for ...

Creating mnemonic phrases can help you remember the order of elements, especially for the first 20 elements or specific groups. These phrases are general and are available on other free online sources ...

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to Dmitri Mendeleev and Lothar Meyer and the ...