2. How many protons, neutrons, electrons are in an ion of sulfur (#S^-2#)?
The atomic number,
For a neutral atom, if there are 16 positive nuclear charges, there must necessarily be 16 negatively charged particles, 16 electrons, whizzing about the nucleus.
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