The periodic table is a way in which to display chemical elements in order of their atomic number. It is used in the fields of chemistry and physics and lists all items with their atomic numbers and their symbol letters. For example copper that is used to make 15mm Copper Pipe like the ones from watkinspowis.co.uk/products/copper-pipe-fittings-and-press-systems/ has an atomic number of 29 and a shortened symbol of Cu.
The first periodic table that was accepted and in general use was created by Dmitri Mendeleev back in 1869. He was the one who placed the elements in the table in order of their atomic number. Not all elements had been discovered so there were gaps left in the table.
The 94 elements that appear first in the table are those elements that are found naturally in the environment, The elements that come after this are created in a lab, by mixing other elements together in some cases. There are 118 in the periodic table, but there are thought to be many more that have yet to be discovered and placed in the table.
There have also been discussions over the years whether some of the elements are in their right places. This has occurred as more and more developments take place in science and more research is undertaken to understand our world and the elements that can be found on it. It will be interesting to see how the periodic table develops in future years.