How come there are no gaps in the table? If there are 118 elements currently, and the next element to be discovered/created has an atomic number of 120, would there just be a gap at 119th position?
How come we managed to find/create every element without any gaps in the periodic table?
In: 104
Technically, the atomic numbers are NOT continuous–they are very much discrete (there is no element 56.7), and based upon the number of protons in the atom. We can always add a proton to a nucleus and increase the atomic number by 1–which is why you say they are “continuous”. The resulting element may not be stable and may very quickly decay.
Interestingly enough, the early periodic table was originally developed by Mendelev in 1869–preceeding the discovery of the electron (1897), the proton (1917), and neutron (1932). The atoms were arranged by atomic weight and not by atomic number. Mendelev (and others) noticed that there was a periodicity of the behavior of the then 64 known elements. He noticed that there were “holes” in his table, and (correctly) predicted new elements and their general properties that filled the holes.
Overtime chemist and scientists discovered new elements and placed them in the correct positions. The last sub-uranium element to be discovered was Promethium (61) in 1945. The lowest atomic number element yet to be discovered in the twentieth century was Technitium (43) discovered in 1937.
Several of the last found sub-uranium elements do not exist in the Earth’s crust in any non-negligible quantity. They were generally found in uranium ore and were transitory steps in the decay chain of uranium.
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