friedrich ernst dorn changed the periodic table to atomic number.
friedrich ernst dorn changed the periodic table to atomic number.
who changed the periodic table to atomic number?
friedrich ernst dorn
following the discovery of the atomic nucleus by ernest rutherford in 1911, it was proposed that the integer count of the nuclear charge is identical to the sequential place of each element in the periodic table. in 1913, henry moseley using x-ray spectroscopy confirmed this proposal experimentally. moseley determined the value of the nuclear charge of each element and showed that mendeleev's ordering actually places the elements in sequential order by nuclear charge. nuclear charge is identical to proton count and determines the value of the atomic number ("z") of each element. using atomic number gives a definitive, integer-based sequence for the elements. moseley predicted, in 1913, that the only elements still missing between aluminium ("z" = 13) and gold ("z" = 79) were "z" = 43, 61, 72, and 75, all of which were later discovered. the atomic number is the absolute definition of an element and gives a factual basis for the ordering of the periodic table. in other words, since the atomic number of an element is the same as the number of protons in its nucleus, the modern periodic table arranges the elements according to their atomic number, and relative to their atomic mass, the way mendeleev did. the periodic table is used to predict the properties of new synthetic elements before they are produced and studied.
periodic table
swedish physicist karl siegbahn continued moseley's work for elements heavier than gold ("z" = 79), and found that the heaviest known element at the time, uranium, had atomic number 92. in determining the largest identified atomic number, gaps in the atomic number sequence were conclusively determined where an atomic number had no known corresponding element; the gaps occurred at atomic numbers 43, 61, 72, 75, 85, and 87.









































section::::looking for expansions and the end of the periodic table.
history of the periodic table