Balance Al2O3 + NaOH + H2O = NaAl(OH)4

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?

Identify the electromagnets with poles that are reversed from the electromagnet shown above

Light waves can move through , but they travel fastest when they move through a(n) .