Answer:
there are as many atoms in a normal breath of air as there are breathfuls of air in the atmosphere of the world
Explanation:
Drift velocity is equal to displacement of the moving object per unit time. The SI unit for displacement is meters while that of time is second. Hence the derived SI unit of velocity is meter per second. This also applies to electron mobility which relates to the displacement per unit time of a moving electron
Colored sparks and rusting.