what would be the new pressure if 250 cm³ of gas at standard pressure is compressed to a volume of 150 cm³? (t, n = constant)

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.

The mass has escaped into a gas which you can not see so the law stays true.