Answer
$^{32}_{16}$S$^{2-}$
Work Step by Step
Chemical symbols come in the form with the mass number as a superscript and the atomic number as a subscript both preceding the atomic symbol, and the charge of the atom following the atomic symbol. The mass number is 32 because the atom has 16 protons and 16 neutrons, and 16+16=32. The atomic number is the number of protons, and this is also what determines the identity of the atom. Because this atom has 16 protons, it is Sulfur, which has the atomic symbol "S". The charge on this atom is 2- because there are 18 electrons, which means there are 2 more electrons than there a protons, giving the atom a negative charge with a magnitude of 2.
