Aunit of matter which cannot be broken down into other substances by ordinary chemical methods is: a. an element b. a compound c. a molecule d. a mineral

a. ELEMENT: A substance that cannot be decomposed (broken down) into simpler substances by ordinary chemical means.

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.