The process of boiling a mixture so that one part will evaporate, then cooling or condensing the evaporated liquid, and finally collecting the cooled liquid, is known as
a. settling.
b. filtration.
c. distillation.
d. evaporation.

The answer is C. Distillation. Distillation is a common process for separating liquid mixtures by using the principle of volatility and boiling point. For a liquid mixture with two liquid components A and B, A will have a lower boiling point or higher volatility than B. By boiling the mixture at the boiling point of component A, only component A will evaporate from the mixture. The evaporated gas will then be cooled to condense component A back to a liquid.

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.