The applet doesn't show the entire periodic table in its most up-to-date form;
there are at least 114 elements now known. But it's not hard to figure out
where those heaviest elements fit into the table; after 5f is full, they'll
fill 6d, 7p... Furthermore, there can't be that many elements left to
find. For reasons I won't go into here, the theory of quantum mechanics tells
us that there can't be elements whose atomic number is larger than 137.