There are 118 elements in a periodic table. The very first one is hydrogen. The last one is oganesson, The four which have been the most recently discovered are 113, 115, 117, and 118. As elements are discovered, they are added to the table once it has been confirmed by scientists that they are indeed legitimate.
The official doccumenting Service that enlists all of the 118 elements and confrims the legitimacy of new ones is called the International Union of Pure and Applied Chemistry. The periodic table is the official recording of all elements that are in existance. Some of the elements are Natural but some are not. It is projected that there will continue to be more elements added as man is always inventing new elements.