In 1911, Ernest Rutherford gave a model of the atom in which a central nucleus held most of the atoms mass and a positive charge which, in units of the electrons charge, was to be approximately equal to half of the atoms atomic weight, expressed in numbers of hydrogen atoms. This central charge would thus be approximately half the atomic weight (though it was almost 25% different from the atomic number of gold , ), the single element from which Rutherford made his guess). Nevertheless, in spite of Rutherfords estimation that gold had a central charge of about 100 (but was element  on the periodic table), a month after Rutherfords paper appeared, Antonius van den Broek first formally suggested that the central charge and number of electrons in an atom were exactly equal to its place in the periodic table (also known as element number, atomic number, and symbolized Z'). This eventually proved to be the case.