Homogeneous mixture definition in chemistry

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?

How have the greenhouse gasses increased from the year 2000 to 2018