The periodic table contains a wide array of elements, numbered from one (hydrogen) to 118 (oganesson), with each number representing the number of protons stored within an atom’s nucleus. Scientists are constantly working to create new elements by cramming more and more protons into nuclei, expanding the periodic table. The effort sparks curiosity and questions: Can the table be enlarged in the opposite direction? Is it possible to make an element zero? Does it already exist?
http://www.realclearscience.com/blog/2017/01/16/is_there_an_element_zero.html