If they are not discovered yet how would we know how many? Also, your question is phrased poorly.
There are 117 elements on the periodic table, however, there is one blank spot that lies on the periodic table of elements, it has the atomic number of 117. If it were discovered, there would be 118 elements on the periodic table of elements.
There were 102 known elements on the periodic table in 1960.
118
The current periodic table contains 118 elements, as of April 2010, but many more may still be discovered.
There were 3 blank spaces in mendeleev's Periodic Table. He left it for the elements which were not discovered at that time.
62
10
There were around 52 known elements in the periodic table in 1834. The periodic table was still in its early stages of development during this time, and many elements were discovered and added to the table in the years that followed.
There are 53 Elements in the Periodic Table.
there are about 125 or120 and some haven't even been discovered yet. so there's a good number of elements in the periodic table
there are precisely 118 elements on the periodic table.
By 1869, a total of 63 elements had been discovered and reported in the scientific literature. These elements formed the basis for Mendeleev's development of the periodic table.