Suppose you were constructing a time line of developments that contributed to the modern model of the atom. Place the following events in the order that they would appear on the time line. Begin with the
earliest event.

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.

Hydrogen is the most abundant element on the periodic table..hope it .

Outermost (valence) electrons