A 4.05 mol sample of Kr has a volume of 311 mL. How many moles of Kr are in a 6.55 L sample at the same temperature and pressure

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.

Just took the quiz on edgenuity and the correct answer is "c.  4.54 x  10–12  j"

I'm sorry but i'm only grade