Now we need N, which we can find using hashira techniques he showed up in class 1 mole of a substance is the the amount of mass of a substance that contains 6.02x10^23 particles (also this is just a thing you have to know like Planck's constant) The mass number of an element determines it's mass which equals 1 mole (e.g. if and element E has a mass number of 50 then 50g of that substance contains 6.02x10^23 particles) We're dealing with the element Po 218, 218 is it's mass number, therefore...