m(O2) = 8 g
N(O) - ?
n(O2) = 8 / 16 = 0.5 mol
N(O2) = 0.5 * 6.02*10^23 = 3.01 *10^23 молекул
N(O) = 3.01*10^23 * 2 = 6.02*10^23 = 0.602*10^24 атомов
