 Okay, so this question asks how many moles, well, it says a typical cloud seed is NACL crystal and it gives the molecular weight of NACL condensed from ocean water with a mass of 4.33 times 10 to the negative 13th ring. How many moles of NACL are present in the clouds? So essentially what this question is asking is how many moles of NACL are present in 4.33 times 10 to the negative 13th rings, okay? So it gives the molecular weight also, so molecular weight equals of NACL equals 58.44 AMU. Okay, so the molar mass of NACL is 58.44 grams per one mole. And the mass of NACL is 4.33 times 10 to the negative. So it's asking how many moles are present in this? Number of moles of NACL that's going to equal the mass essentially divided by the molar mass or because you get 3.33.